(CNN) From half a world away, Maritha Strydom was following her daughter's progress on Mount Everest last week through a series of satellite "pings" from the climber's phone. 
 
 Then the pings stopped. And soon after Strydom got the news every parent dreads -- not through a phone call, she says, but by reading a news article online. 
 
 Her daughter, Maria Strydom, had died of altitude sickness in the arms of her husband, Robert Gropel, Saturday as the couple attempted to climb the world's tallest peak to prove that vegans can do anything. She was one of four climbers who died on Everest in a grim span of four days. 
 
 "I was worried when the pings stopped, and we started calling but no one could give us any answers," Strydom told CNN in an interview from Brisbane, Australia. "So my other daughter ... Googled and found in the Himalayan Times that my daughter had passed away." 
 
 Strydom still wants answers. 
 
 She believes her daughter, known by friends and family as Marisa, was in the "death zone" for too long. 
 
 The death zone refers to altitudes higher than 8,000 meters (about 26,200 feet), where the risk of dying significantly climbs. There is little oxygen here, so altitude sickness is common and can be deadly. Temperatures tumble, winds intensify and frostbite can hit any exposed part of the body. The ground is icy, so falls are not uncommon. 
 
 "No one is supposed to stay in the death zone longer than 16 to 20 hours. If you stay there longer you will be dead," Strydom told CNN. 
 
 South African-born Maria Strydom, 34, worked as a finance professor with the Monash Business School in Melbourne, Australia. She had told the school in an interview that she and Gropel had decided to climb the highest peak on each of the seven continents -- the so-called "seven summits" -- to prove that vegans are strong. 
 
 The couple reached Everest's South Summit on Friday but decided to turn around and descend when Strydom began feeling poorly, according to an online post by exhibition leader Arnold Coster . Several Sherpas and her husband struggled to carry her down the mountain, but she collapsed the next morning, Coster said. Gropel was evacuated to Kathmandu the next day by helicopter. 
 
 "She felt weak and decided to turn around ... What Rob knows is that she felt ill, she got medication, she looked a bit better, and when he tried to get her down to camp 3, she suddenly collapsed," Strydom said. 
 
 "There's a massive gap in between the last ping where she turned around and where the story continues, and no one can tell me what happened in between yet, and I don't think I'll find out before Rob is better and, you know, he can tell us what happened," Strydom said, adding that Gropel was still suffering from altitude sickness. 
 
 "I am very, very concerned. I'm concerned about a lot of things," she added. "In their itinerary it was suggested they would sleep over at camp 3 for their acclimatization. They didn't." 
 
 Photos: Exploring Mount Everest Photos: Exploring Mount Everest The journey to the summit of Mount Everest is a challenge an increasing number have taken on since the summit was first reached in 1953 by Sir Edmund Hillary and Tenzing Norgay. Until the late 1970s, only a handful of climbers per year reached the summit. By 2012 that number rose to more than 500. Hide Caption 1 of 23 Photos: Exploring Mount Everest Explorers are seen in 1922 at Camp II on the East Rongbuk Glacier. That same year, seven Sherpas were killed when they were caught in an avalanche during an expedition led by George Mallory. Hide Caption 2 of 23 Photos: Exploring Mount Everest George Mallory and Edward Felix Norton reach 27,000 feet on the northeast ridge of Everest in 1922. They failed to reach the summit. Hide Caption 3 of 23 Photos: Exploring Mount Everest Mallory returns to Everest In June 1924. He's seen here with his climbing partner Andrew Irvine at base camp. This is the last photo of the the two before they disappeared on the mountain. Mallory's body was found 75 years later, showing signs of a fatal fall. Hide Caption 4 of 23 Photos: Exploring Mount Everest Mountaineers are seen preparing to leave their camp during one of Eric Shipton's early expeditions on Everest in the 1930s. While Shipton never made it to the summit, his exploration of the mountain paved the way for others. Hide Caption 5 of 23 Photos: Exploring Mount Everest Shipton leads an expedition exploring the Khumbu Glacier icefall in November 1951. Hide Caption 6 of 23 Photos: Exploring Mount Everest Shipton is also known for discovering and photographing footprints of an unknown animal or person, like this one taken in 1951. Many attributed these to the Yeti, or Abominable Snowman. Hide Caption 7 of 23 Photos: Exploring Mount Everest Edmund Hillary sits at base camp in May 1953 before heading out on what would become the first successful ascent to the top of the world. Hide Caption 8 of 23 Photos: Exploring Mount Everest Hillary and Nepalese-Indian mountaineer Tenzing Norgay climb beyond a crevasse on Mount Everest in 1953. Upon meeting George Lowe, who had climbed up to meet the descending duo, Hillary reportedly exclaimed, "Well George, we knocked the bastard off!" Hide Caption 9 of 23 Photos: Exploring Mount Everest Members of a U.S. expedition team and Sherpas are shown with their climbing gear on Everest. The team, led by Jim Whittaker, reached the top on May 1, 1963, becoming the first Americans to do so. Hide Caption 10 of 23 Photos: Exploring Mount Everest Whittaker's team members climb Everest's West Ridge in 1963. Hide Caption 11 of 23 Photos: Exploring Mount Everest On April 5, 1970, six Sherpas died in an avalanche at the Khumbu Icefall. The icefall, at the head of the Khumbu Glacier, seen here in 2003, is one of the more treacherous areas of the ascent. Hide Caption 12 of 23 Photos: Exploring Mount Everest British Army soldiers and mountaineers John "Brummie" Stokes and Michael "Bronco" Lane above the icefall at the entrance to the West Col (or western pass) of Mount Everest during their successful ascent of the mountain. The joint British-Nepalese army expedition reached the summit on May 16, 1976. Hide Caption 13 of 23 Photos: Exploring Mount Everest In 1978, Reinhold Messner makes the first ascent without supplemental oxygen. Messner is seen here at Munich Airport showing reporters his frozen thumb after climbing to the top of Nanga Parbat in Pakistan, alone and without an oxygen mask. Hide Caption 14 of 23 Photos: Exploring Mount Everest French climber Jean-Marc Boivin becomes the first person to paraglide from Everest's summit in September 1998. Hide Caption 15 of 23 Photos: Exploring Mount Everest The 1996 climbing season was one of the deadliest, when 15 people died on Everest, eight in a single storm in May of that year. Hide Caption 16 of 23 Photos: Exploring Mount Everest Francys Distefano-Arsentiev became the first American woman to reach Everest's summit without bottled oxygen on May 23, 1998. However, she and her husband, Sergei Arsentiev, never made it off the mountain. They died after becoming separated while attempting to descend in the dark. At least one climbing party found Francys barely conscious, but there was nothing they could do to save her. Her husband's body was found years later. It is believed he fell while trying to save his wife. Hide Caption 17 of 23 Photos: Exploring Mount Everest Pemba Dorje Sherpa and Moni Mulepati became the first people to get married on Everest's summit, on March 30, 2005. The couple are seen here waving from base camp on June 2, 2005. Hide Caption 18 of 23 Photos: Exploring Mount Everest Sherpa climbers pose at Everest Base Camp after collecting garbage during the Everest cleanup expedition on May 28, 2010. A group of 20 Nepalese climbers collected nearly two tons of garbage in a high-risk expedition to clean up the world's highest peak. Hide Caption 19 of 23 Photos: Exploring Mount Everest Mountaineer Ralf Dujmovits took this image of a long line of climbers heading up Everest in May 2012. Hide Caption 20 of 23 Photos: Exploring Mount Everest Jordan Romero became the youngest person to reach the summit, at age 13, on May 22, 2013. Jordan, right, is seen here on the summit with one of the Sherpas who helped him make the ascent. Hide Caption 21 of 23 Photos: Exploring Mount Everest Yuichiro Miura, became the oldest person to summit Everest, on May 23, 2013, at the age of 80. Hide Caption 22 of 23 Photos: Exploring Mount Everest Malavath Poorna, left, holds up her national flag on May 24, when the 13-year-old daughter of poor Indian farmers became the youngest girl to climb Everest. Hide Caption 23 of 23 
 
 Strydom also is upset that she had to learn of her daughter's death on the Internet. 
 
 "For two, three days not a word," she said. Someone finally called her on Tuesday, she said. 
 
 Now Strydom is focused on retrieving Marisa's body from Everest and returning her to Australia. 
 
 "We are totally devastated. Everything we did was to get her body back, because they just abandon bodies on the mountain if they're dead. If you're alive, they try to rescue you, like they did with Rob. If you didn't survive they leave you on the mountain. So our whole fight was just to get her off that mountain and back home," she said. 
 
 "I don't know how I'm going to live without her, but if she was abandoned on that mountain, I know I wouldn't have made it," she said. "It's the toughest thing that ever happened to me. Such a lovely girl, so talented so giving, and a life wasted." ||||| Rajan Pokhrel 
 
 KATHMANDIU: Mt Everest witnessed another casualty after an Australian woman climber died near the Camp IV on Nepal side on Saturday, officials confirmed. 
 
 Dr Maria Elizabeth Strydom lost her life after she suffered from snow blindness followed by stroke, according to Shiva Bahadur Sapkota, a liaison officer deputed by the Department of Tourism at the Everest base camp. 
 
 The Australian national was accompanied by her husband during the expedition. 
 
 A Finance lecturer at Monash Business School under Monash University, Dr Strydom (34) was heading to the world’s highest peak when she was taken ill, according to Mingma Sherpa, the owner of Seven Summit Treks, which locally managed their expedition. 
 
 Dr Strydom had already climbed Mt Denali in Alaska, Mt Aconcagua in Argentina, Mt Ararat in eastern Turkey, and Mt Kilimanjaro in Africa, among other peaks. 
 
 Earlier in the wee hours of Saturday, Eric Arnold, who hailed from Rotterdam of the Netherlands, died at the Camp IV after suffering from altitude-related sickness. 
 
 READ ALSO: Foreign climber who perished on Mt Everest is Dutch 
 
 Follow The Himalayan Times on Twitter and Facebook ||||| Maria has been an invaluable member of St Michael’s Netball Club for 10 years. 
 
 She was an incredibly generous person who volunteered her time and expertise as club treasurer on our committee. 
 
 It is because of people like Maria that community run clubs like ours are able to function. 
 
 She was a leader, our team mate and most importantly our friend. 
 
 With the blessing of her husband Rob and her family, we began collecting money to support their efforts to retrieve and repatriate Maria’s body. 
 
 We achieved our goal 
 
 Maria was repatriated to Melbourne and was farewelled by her family and friends at a memorial service on 8th June 2016 at the Monash University Religious Centre, Clayton Campus.
– The mother of a vegan who died trying to climb Mount Everest is demanding answers—about whether the climb was conducted safely and why, for days, no one informed her that her daughter was dead. Speaking from Australia, Maritha Strydom tells CNN she was following satellite "pings" of daughter Maria Strydom's climb last Saturday when the signal blanked out. "I was worried when the pings stopped, and we started calling but no one could give us any answers," says Maritha. "So my other daughter ... Googled and found in the Himalayan Times that my daughter had passed away." What's more, Maritha and her daughter heard "not a word" about the tragedy—one of four Everest deaths over a four-day span—until they received a call on Tuesday. Maritha also says guides let Maria and husband Robert Gropel stay too long in the so-called "death zone," an oxygen-poor area around 26,200 feet where altitude sickness and frostbite are common dangers. Maria "felt weak and decided to turn around," her mom says, but when Maria got medication and tried climbing back down, "she suddenly collapsed." Now Maritha is trying retrieve her daughter's body from the mountain, where survivors are often rescued and victims get left behind (here's the fundraising page to pay for her return to Australia). Seems Maria and her husband each paid $34,500 for the climb in a pretty sketchy, unregulated market: "You [can] have a circumstance of unskilled people leading other unskilled people in the most dangerous mountain environment you can get," veteran climber Andrew Lock tells the Australian. (Maria was trying to prove that a Vegan could climb Everest.)