This March 10, 2018 photo shows an early morning view of the main span of the a pedestrian bridge that is being positioned to connect the City of Sweetwater, Fla., to Florida International University... (Associated Press) 
 
 This March 10, 2018 photo shows an early morning view of the main span of the a pedestrian bridge that is being positioned to connect the City of Sweetwater, Fla., to Florida International University near Miami. The 950- ton new bridge collapsed Thursday, March 15, over several cars causing several... (Associated Press) 
 
 MIAMI (AP) — As Florida authorities work to identify the people who died in Thursday's catastrophic bridge collapse, state and federal investigators will begin the task of figuring out how and why the five-day-old span failed. 
 
 Miami-Dade County Fire Chief Dave Downey said Thursday night that his crew is using high-tech listening devices, trained sniffing dogs and search cameras in a race to find anyone still alive in the rubble. The $14.2 million pedestrian bridge was supposed to open in 2019 as a safe way for students to cross the busy road. It linked the community of Sweetwater with the campus of Florida International University. 
 
 "We have to remove some of this piece by piece. It's very unstable." Aerial footage at the site showed a trained dog running atop fallen concrete and sniffing in the crevices for any victims," he said. 
 
 But Miami-Dade Police Director Juan Perez acknowledged the likelihood of finding more victims under the rubble is slim. 
 
 "We know that there's going to be a negative outcome at the end of the day," Perez said. 
 
 Four people were found dead and at least nine others were injured and taken to local hospitals; officials at one point said 10 were injured. 
 
 Florida Gov. Rick Scott and U.S. Sen. Marco Rubio attended the evening briefing. 
 
 Rubio said the public and the families of the dead and injured deserve to know "what went wrong." 
 
 Scott added that an investigation will get to the bottom of "why this happened and what happened." He said that if anyone did anything wrong, "we will hold them accountable." 
 
 National Transportation Safety Board chairman Robert Sumwalt III said a team of specialists was heading to Miami on Thursday night with plans to begin its investigation Friday morning. 
 
 Rubio, who is an adjunct professor at the school, noted the pedestrian bridge was intended to be an innovative and "one-of-a-kind engineering design." 
 
 An accelerated construction method was supposed to reduce risks to workers and pedestrians and minimize traffic disruption, the university said. The school has long been interested in this kind of bridge design; in 2010, it opened "The ABC (accelerated bridge construction) Center," to help bridge professionals. Other universities around the country partnered with FIU to "provide the transportation industry with the tools needed to effectively and economically utilize the principles of ABC to enhance mobility and safety, and produce safe, environmentally friendly, long-lasting bridges." 
 
 Renderings showed a tall, off-center tower with cables attached to the walkway to support it. When the bridge collapsed, the main tower had not yet been installed, and it was unclear what the builders were using as temporary supports. 
 
 The project was a collaboration between MCM Construction, a Miami-based contractor, and Figg Bridge Design, based in Tallahassee. Figg is responsible for the iconic Sunshine Skyway Bridge across Tampa Bay. 
 
 Figg issued a statement Thursday saying the company was "stunned" by the collapse and promising to cooperate with investigations. 
 
 "In our 40-year history, nothing like this has ever happened before," the company's statement said. "Our entire team mourns the loss of life and injuries associated with this devastating tragedy, and our prayers go out to all involved." 
 
 MCM Construction Management, which is building the bridge, posted a message to the company's Facebook page promising "a full investigation to determine exactly what went wrong." 
 
 Robert Bea, a professor of engineering and construction management at the University of California, Berkeley, said it was too early to know exactly what happened, but the decision to use what the bridge builders called an "innovative installation" was risky, especially because the bridge spanned a heavily traveled thoroughfare. 
 
 "Innovations take a design firm into an area where they don't have applicable experience, and then we have another unexpected failure on our hands," Bea said after reviewing the bridge's design and photos of the collapse. 
 
 The FIU community, along with Sweetwater and county officials, held a "bridge watch party" March 10. That's when the span was lifted from its temporary supports, rotated 90 degrees across an eight-lane thoroughfare and lowered into its permanent position over the busy road. 
 
 FIU President Mark Rosenberg said during a news conference that tests were being done on Thursday. Authorities said two construction workers were on the bridge when it collapsed; it's unclear what the tests were or if they contributed to the failure. 
 
 "This bridge was about goodness, not sadness," Rosenberg said. "Now we're feeling immense sadness, uncontrollable sadness. And our hearts go out to all those affected, their friends and their families. We're committed to assist in all efforts necessary, and our hope is that this sadness can galvanize the entire community to stay the course, a course of goodness, of hope, of opportunity." 
 
 ___ 
 
 Associated Press writers Jason Dearen in Gainesville, Kelli Kennedy in Fort Lauderdale, David Fischer and Curt Anderson in Miami and Tamara Lush in St. Petersburg contributed to this report. ||||| The death toll rose overnight in the catastrophic collapse of a 950-ton pedestrian bridge at Florida International University in Miami-Dade County, as a search for survivors became a mission to recover bodies, police said before dawn Friday. 
 
 At least six people are confirmed dead, Miami-Dade Police Detective Alvaro Zabaleta told reporters at the scene along a normally busy, eight-lane thoroughfare where the 174-foot-long bridge came down Thursday afternoon. 
 
 Five people died at the scene and another person died at the hospital, Zabaleta said. 
 
 At least one of the deceased was an FIU student, Sweetwater Mayor Orlando Lopez said during a second press conference Friday morning. Students had been on spring break and the campus was less busy than usual this week. 
 
 Authorities withheld victims’ names. The death toll could rise, Zabaleta warned. 
 
 “There is the possibility, the sad possibility, that under the concrete there may be additional vehicles.” Zabaleta said. 
 
 At least eight vehicles were beneath the broken concrete slabs, officials have said. 
 
 Miami-Dade Police Director Juan Perez said for the time being, they would not provide information about casualties. 
 
 “We’re not going to talk numbers anymore,” Perez said about updating tallies of the injured and the dead. “We expect to find other individuals down there. So what’s probably best is we wait to find all the vehicles and we’ll give you a grand total of the fatalities and the magnitude of this event.” 
 
 A new 950-ton pedestrian bridge at Florida International University in Miami-Dade county collapsed Thursday afternoon, killing an unknown number of people. 
 
 The bridge was put in place Saturday and was to be completed in 2019. It crossed Southwest Eighth Street and was intended to be a safe passageway for students and connect the school’s campus to the city of Sweetwater to the north. 
 
 State and federal investigators began Friday to figure out why the span failed. 
 
 The university was open Friday. A main entrance to campus was closed because traffic along Southwest Eighth Street between Southwest 107th Avenue to Southwest 117th Avenue will be detoured indefinitely. 
 
 “The people of South Florida have been through a lot, obviously, over the last several weeks, ” National Transportation Safety Board chairman Robert Sumwalt III said Friday, referring to the Feb. 14 mass shooting at Marjory Stoneman Douglas High School in Parkland, when 17 were killed and 17 wounded. “And this is just yet one more tragedy to add to that sad book.” 
 
 A “go team” of specialists, including experts in civil engineering and materials science from NTSB will study the failed project. He expects the NTSB team to work on the scene for five to seven days. Investigators from the Occupational Safety and Health Administration were also working at the fallen bridge. 
 
 “Our entire purpose is to find out what happened so we can keep it from happening again,” Sumwalt said. 
 
 Authorities declined to address reports about whether the bridge had undergone testing before the Thursday afternoon collapse. 
 
 “Those are answers we’re looking for was well,” said Perez, the county police director. He added that the entire project, from contract to catastrophe, will be reviewed and will go on long after the broken concrete and victims are removed. 
 
 U.S. Senator Marco Rubio had tweeted Thursday night, “The cables that suspend the #Miami bridge had loosened & the engineering firm ordered that they be tightened. They were being tightened when it collapsed today.” 
 
 Miami-Dade County Deputy Mayor Maurice Kemp said Friday, “We have not confirmed that there was a stress test. The key here is not to jump to conclusions, not to speak on speculations, but to work on fact. And that’s what we plan to do.” 
 
 Steps taken Friday will include moving in heavy equipment to break the largest, still solid piece of concrete and remove it so victims can be recovered, what Perez called a “tedious process. Our goal is to get everything removed so we can get to those victims.” 
 
 Firefighters got the call for help at 1:30 p.m. Thursday. Search and rescue crews worked into the night to try to find survivors. 
 
 The $14.2 million bridge, which FIU said “swung into place” on Saturday, had not yet opened to the public. 
 
 Witness Susie Bermudez told WTVJ-Ch. 6 she was driving toward the bridge when she saw it fall. 
 
 "There’s probably like seven or eight cars under the bridge, so it was very shocking to me, and I’m very grateful to be alive," Bermudez said. 
 
 Gov. Rick Scott and Rubio flew to Miami Thursday night and while speaking from the college campus, pledged to figure out what led to the collapse. 
 
 “There will clearly be an investigation to find out exactly what happened and why this happened and we will hold anybody accountable if anybody has done anything wrong,” Scott said Thursday. “But the most important thing we can do right now is pray for the individuals that ended up in the hospital, for their full recovery, and pray for the family members that have lost loved ones.” 
 
 Rubio, who has taught at the university as an adjunct professor for the last decade, said the bridge was built as a safety feature after a student was killed while crossing the busy street there last year. 
 
 “It was also going to be a signature project, one that people would identify with the school and this community, and one of a kind in terms of its engineering design,” Rubio said. “To see it on the ground there today and underneath it those who lost their lives as a result of this and those who have been injured, it’s just so tragic. 
 
 “There will be an exhaustive review that will get details on an engineering and scientific level as to what the errors were and what led to this catastrophic collapse, of that you can rest assured … The public deserves to know and the families of those who have been hurt and lost their lives deserve to know what went wrong.” 
 
 It was unknown how long the investigations and reviews could take. 
 
 Photographs from the scene showed a partially crushed cranberry-colored sedan, its rear end trapped beneath the rubble, its front end free from debris. The grilles of two other vehicles could be seen beneath the edge of a concrete slab. ||||| UPDATE: As of Friday morning, six people are confirmed dead. 
 
 A pedestrian bridge under construction collapsed Thursday, just days after crews had dropped an elevated 950-ton span in place on a signature project that was intended to give Florida International University students a safe route across the busy roadway. 
 
 The massive span — in a sudden, catastrophic failure — crashed down across eight lanes of heavily traveled Tamiami Trail, flattening eight cars. The death toll remained uncertain as rescue crews continued to work into the night to reach vehicles but late Thursday Miami-Dade fire chief Dave Downey confirmed at least four people had been killed, including a student from FIU, police sources said. 
 
 Nine people had been pulled from the rubble by evening and rushed to Kendall Regional Medical Center’s trauma unit, including two who required immediate surgery. The others sustained injuries ranging from scrapes and bruises to broken bones, which were not considered life threatening. On campus, some families waited for word on missing loved ones. 
 
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 Even before the dust from the disaster settled, motorists scrambled from their cars to help. At least one woman, Katrina Collazo, was pulled from her half-crushed car, miraculously unscathed. 
 
 “Thank God ... my daughter is alive,” said her mother, Ada Collazo, in Spanish, after rushing to the scene, fearful that another family member also might have been riding in the back. “I thought my granddaughter was in the car, but she wasn’t. She’s in school.” 
 
 Collazo said her daughter, who had been on campus for a nursing meeting, stopped at a red light when she said she heard what sounded like small rocks falling on her car. As she turned around, the span mashed everything behind the driver seat. The car next to her was not as lucky. That vehicle was flattened like an aluminum can. 
 
 The FIU bridge collapsing... I’m still in shock pic.twitter.com/ZNqO2z5ch6 — Megan (@meganmfernandez) March 15, 2018 
 
 It was not immediately clear what caused the collapse of a $14.2 million structure FIU had touted as an innovative “instant” bridge because of construction techniques intended to speed up the work and minimize disruption to commuter traffic. The bridge’s main 175-foot span, assembled on the side of the road, was raised into place across Tamiami Trail on Saturday in less than six hours. But the project was far from complete and not expected to open to student foot traffic until 2019. 
 
 Several witnesses reported that two workers were on the bridge when it collapsed shortly before 2 p.m. Early in the day, Miami-Dade Mayor Carlos Gimenez said the bridge had undergone a “stress test” but it was unclear what, if any, role that might have played in the failure. FIU President Mark Rosenberg confirmed there was testing on the bridge sometime before the collapse, but said the testing was proper. 
 
 “I have not spoken directly to Munilla Construction, but I am satisfied that the testing that was occurring was consistent with best practices," Rosenberg said shortly after 8 p.m. “I’m not an engineer, so I'm not privy to those details. I know that tests occurred today. And I know, I believe, that they did not prove to lead anyone to the conclusion that we would have this kind of a result. But I do not know that as a fact.” 
 
 Late Thursday, came the first definitive word from a government official about what was being done on the bridge when it fell. U.S. Sen. Marco Rubio, R-FL, said in a Twitter post that: “The cables that suspend the #Miami bridge had loosened & the engineering firm ordered that they be tightened. They were being tightened when it collapsed today.” 
 
 Rubio, a Miami Republican, did not elaborate on the information. But he was in a position to know inside details about the catastrophe. 
 
 He traveled to the FIU campus Thursday on same plane with Rosenberg. He said he spoke to MCM partner Pedro Munilla amid the rubble and he attended private briefings at FIU. 
 
 The late post came soon after Gov. Rick Scott and Rubio both promised swift investigations. 
 
 “We will hold anybody accountable if anybody has done anything wrong,” Scott said. 
 
 Rubio also vowed an “exhaustive” review with scrutiny of “science and engineering” that went into the project. “The families and the survivors deserve to know what went wrong,” he said. 
 
 The National Transportation Safety Board announced that it was dispatching a team of 15 to examine the collapse and investigators expected to be on site by late Thursday. 
 
 Authorities stressed that it could take days or more to determine what went wrong. But one agency, the Florida Department of Transportation, quickly distanced itself, issuing a fact sheet saying it had a limited role in the project and emphasizing FIU’s responsibility for testing and safely completing the bridge. 
 
 Designed as a cable-supported bridge, the project was a collaboration between MCM Construction, a prominent Miami-based contractor, and FIGG Bridge Design, based in Tallahassee. FIGG is responsible for the iconic Sunshine Skyway Bridge across Tampa Bay. 
 
 FIGG issued a statement Thursday saying the company was “stunned” by the collapse and promising to cooperate with every authority investigating the collapse. 
 
 “In our 40-year history, nothing like this has ever happened before,” the company’s statement said. “Our entire team mourns the loss of life and injuries associated with this devastating tragedy, and our prayers go out to all involved.” MCM Construction Management, which is building the bridge, posted a message to the company’s Facebook page promising “a full investigation to determine exactly what went wrong.” 
 
 Mayor Gimenez, in Hong Kong on a trade mission, said in a telephone interview that he instructed county rescue workers to identify license plates from the trapped cars as quickly as possible so that families could be notified. 
 
 Rescue crews with specially trained dogs and listening devices were poring over the wreckage, hoping to find survivors. About two hours after the collapse, crews also brought in heavy equipment to probe under sections of the shattered span. 
 
 “I don’t know what’s under the bridge, under the rubble,” said Lt. Alex Camacho of the Florida Highway Patrol. “It’s impossible to see.” 
 
 The injured were transported to the trauma center at Kendall Regional. Mark McKenney, chief of the trauma department, said the 10 injured patients ranged in age from 20 to 50 years old, including one man whose heart had stopped beating when he arrived. 
 
 Doctors revived the man, who was not identified, and wheeled him into the operating room. He is listed in critical condition with head and chest injuries. 
 
 A second patient arrived comatose with severe injuries that required orthopedic and neurosurgery, the hospital spokesperson said. The remaining eight patients are in stable condition with injuries ranging from scrapes and bruises to broken bones. 
 
 FIU spokesperson Maydel Santana-Bravo issued a statement, even as rescue crews were still working the scene. 
 
 “We are shocked and saddened about the tragic events unfolding at the FIU-Sweetwater Bridge,” she said. “At this time, we are still involved in rescue efforts and gathering information. We are working closely with authorities and first responders on the scene. We will share updates as we have them.” 
 
 FIU students are on spring break this week, but traffic was expected to be heavy with the Miami-Dade County Youth Fair opening nearby on Thursday. 
 
 President Donald Trump also posted a tweet, “Continuing to monitor the heartbreaking bridge collapse at FIU — so tragic.” 
 
 Students and faculty have long clamored for a bridge at the 109th Avenue crossing, where students on foot have to scurry across heavily traveled Tamiami Trail, which divides the campus from Sweetwater. Though FIU provides shuttles, many students prefer to walk. In August, FIU undergraduate Alexis Dale was hit and killed by a motorist while crossing the intersection. 
 
 The pedestrian walkway was installed in a single morning at Southwest 109th Avenue on Saturday, intended eventually to link FIU’s Modesto A. Maidique Campus to the small suburban city of Sweetwater, where the university estimates 4,000 of its students live. 
 
 FIU, which has an “accelerated bridge construction” program in its engineering school, promoted the project’s innovative approach. A 175-foot section of the overall 320-foot long bridge was fabricated by the side of the Trail while support columns were erected in place. The 950-ton span was lifted off the ground by a mechanical transporter, swung into position across the Trail, then lowered into place over the support columns. That reduced to a minimum the time the trail had to be closed to traffic, and minimized risks to workers and people in the vicinity, FIU said. 
 
 This is a breaking news story and will be updated as more is learned. 
 
 Miami Herald Staff Writers Howard Cohen, Alex Harris, David J. Neal, Charles Rabin, David Smiley, Jennifer Staletovich, Carli Teproff and Martin Vassolo contributed to this report.
– It was supposed to be a "signature project" that people would identify with Florida International University. Instead, it's the scene of a still unexplained tragedy that left at least six people dead. At least nine injured people were pulled from the rubble Thursday after a pedestrian bridge collapsed over eight lanes of traffic near the Miami-area campus, reports the Miami Herald. At least eight cars were flattened by the sudden collapse. Miami-Dade County Fire Chief Dave Downey said Thursday night that rescue workers were using sniffer dogs and high-tech listening devices in the search for survivors, the AP reports. Early Friday, police said the operation had moved from rescue to recovery. The main span of the "instant" $14.2 million bridge connecting FIU to the community of Sweetwater was swung into place on Saturday, though it wasn't scheduled to open to the public until 2019. Sen. Marco Rubio, an adjunct professor at the university, says the bridge was "one of a kind in terms of its engineering design," the Sun Sentinel reports. "There will be an exhaustive review that will get details on an engineering and scientific level as to what the errors were and what led to this catastrophic collapse, of that you can rest assured," he says. There were two workers on the bridge at the time of the collapse, and Rubio tweeted Thursday night that the cables that suspend the bridge had loosened and were being tightened when it collapsed.