Question: How many terrorists were on the second plane to hit the World Trade Center?

Context articles: Planning of the September 11 attacks
World Trade Center Bhubaneswar
4 World Trade Center
Collapse of the World Trade Center
One World Trade Center
Guy F. Tozzoli
United Airlines Flight 175
Flight 175: As the World Watched
World Trade Center (Portland, Oregon)
World Trade Centers Association

On September 11, 2001, 19 Arab-Muslim hijackers took control of four commercial aircraft and used them as suicide weapons in a series of four coordinated acts of terrorism to strike the World Trade Center in New York City, the Pentagon in Arlington County, Virginia, and an additional target in Washington, D.C. Two aircraft hit the World Trade Center while the third hit the Pentagon.
 However, one plane never arrived at its target; it crashed in a field in Pennsylvania because the passengers fought back.
 The intended target is believed to have been either the United States Capitol or the White House.
 As a result, 2,977 victims were killed, making it the most deadly terrorist attack on U.S. soil; also the deadliest foreign attack on U.S. soil, exceeding Japan's surprise attack on Pearl Harbor in Honolulu, Hawaii, on December 7, 1941, which killed 2,403 victims.
 It was carefully planned by al-Qaeda, who sent 19 terrorists to take over Boeing 757 and Boeing 767 aircraft, operated by American Airlines and United Airlines.
World Trade Center Bhubaneswar (also known as WTC Bhubaneswar) is a 40 floors tall building in Bhubaneswar, Odisha, India.
 This will be the fifth World Trade Centre to be operationalised in India and the 344th in the world.
 It is developed by Populous (company).
 The center will consist of 200 room hotel, 50,000 sqft of indoor exhibition hall, multipurpose convention hall to accommodate 4000 delegates, small convertible meeting halls to host 12 - 16 events simultaneously, an open area to accommodate up to 25,000 people and an open amphitheatre.
 The World Trade Center Bhubaneswar will be tallest building in Odisha.
 The Convention Center will be connected to all nearby hotels and the World Trade Center through a skywalk.
 For now, the World Trade Center Bhubaneswar is functioning from IDCO Towers, in Janpath, Bhubaneswar.
4 World Trade Center (also known by its street address, 150 Greenwich Street) is a skyscraper that is part of the World Trade Center complex in New York City.
 It opened to tenants and the public on November 13, 2013.
 It is located on the southeast corner of the 16 acre World Trade Center site, where the original nine-story 4 World Trade Center stood.
 Pritzker Prize-winning architect Fumihiko Maki was awarded the contract to design the 978 ft building.
 s of 2016 , it is the third tallest skyscraper at the rebuilt World Trade Center, behind One and 3 World Trade Center.
 However, 2 World Trade Center is expected to surpass the height of both buildings upon completion.
 The total floor space of the building includes 1.8 million square feet (167,000 square meters) of office and retail space.
 The building's groundbreaking took place in January 2008.
The Twin Towers of the World Trade Center collapsed on September 11, 2001, as a result of being struck by two jet airliners hijacked by 10 terrorists affiliated with al-Qaeda, during the September 11 attacks.
 Two of the four hijacked airliners crashed into the Twin Towers, one into the North Tower (1 World Trade Center) and the other into the South Tower (2 World Trade Center).
 The collapse of the Twin Towers destroyed the rest of the complex, and debris from the collapsing towers severely damaged or destroyed more than a dozen other adjacent and nearby structures.
 The South Tower collapsed at 9:59 am, less than an hour after being hit by the second hijacked airliner, and at 10:28 am the North Tower collapsed.
 Later that day, 7 World Trade Center collapsed at 5:21 pm from fires that had started when the North Tower collapsed.
 As a result of the attacks to the towers, a total of 2,763 people died.
 Of the people who died in the towers, 2,192 were civilians, 343 were firefighters, and 71 law enforcement officers. Aboard the two airplanes, 147 civilians and 10 hijackers also died.
One World Trade Center (also known as 1 World Trade Center, 1 WTC or Freedom Tower ) is the main building of the rebuilt World Trade Center complex in Lower Manhattan, New York City.
 It is the tallest building in the Western Hemisphere, and the sixth-tallest in the world.
 The supertall structure has the same name as the North Tower of the original World Trade Center, which was destroyed in the terrorist attacks of September 11, 2001.
 The new skyscraper stands on the northwest corner of the 16 acre World Trade Center site, on the site of the original 6 World Trade Center.
 The building is bounded by West Street to the west, Vesey Street to the north, Fulton Street to the south, and Washington Street to the east.
Guy Frederick Tozzoli (February 12, 1922, North Bergen, New Jersey – February 2, 2013, Myrtle Beach, South Carolina) was director of the World Trade Department of the Port of New York Authority in the 1960s.
 As such he was the driving force behind the development of the World Trade Center.
 Tozzoli was also a founder of the World Trade Centers Association, which fostered the development and operation of World Trade Centers globally.
 Tozzoli was the driving force from New York City, while his business associates Soichiro Honda and Paul Fabry led the WTC effort in Tokyo and New Orleans respectively.
 Tozzoli graduated from Fordham University and later served his country as a lieutenant in World War II and the Korean War.
 Tozzoli was credited for hiring Minoru Yamasaki to design the World Trade Center complex which was dedicated in April, 1973.
 Tozzoli retired as Director of the World Trade Department for the Port Authority in 1987, but remained as president of the World Trade Centers Association until January 2011.
United Airlines Flight 175 was a scheduled domestic passenger flight from Logan International Airport, in Boston, Massachusetts, to Los Angeles International Airport, in Los Angeles, California.
 On September 11, 2001, the Boeing 767-200 operating the route was hijacked by five al-Qaeda terrorists and flown into the South Tower of the World Trade Center in New York City, killing all 65 people aboard and an unconfirmed number in the building's impact zone.
Flight 175: As the World Watched is an American television documentary film that premiered in August 2006 on TLC.
 It covers the final moments of the passengers and crew on board United Airlines Flight 175, which was the second commercial airliner to strike the World Trade Center, impacted with the South Tower, and was the most visually documented (both photographed and filmed) flight during the September 11 attacks.
The World Trade Center is a three-building office complex in Portland in the U.S. state of Oregon.
 The main building, One World Trade Center, is a 17-story office tower that is the fifth-largest office tower in Portland with 474867 sqft .
 Completed in 1977, One World Trade Center is 230 ft tall and is topped by a heliport.
 The complex is operated by the World Trade Centers Association and is the headquarters for Portland General Electric.
 There is also a 220-seat theater, known as the World Trade Center Auditorium.
The World Trade Centers Association (WTCA) was founded in 1968 following the establishment of the first World Trade Center in New Orleans and followed later in 1973 by the better known World Trade Center and Twin Tower buildings in New York City.
 WTCA is a not-for-profit, non-political association dedicated to the establishment and effective operation of World Trade Centers (WTCs) as instruments for international trade expansion.
 The association represents 316 members in 91 countries (World Trade Center of Grenoble in France for example).
 The WTCA is an unofficial umbrella trade association that unites corporations and government agencies in international trade.