United Airlines Flight 175 was a domestic passenger flight that was hijacked by five al-Qaeda terrorists on September 11, 2001, as part of the September 11 attacks. The flight's scheduled plan was from Logan International Airport in Boston to Los Angeles International Airport in California. The Boeing 767-200 aircraft, carrying 65 passengers and crew, was deliberately crashed into the South Tower of the World Trade Center in New York City, killing all on-board instantly and causing the deaths of around 600 people at or above the building's impact zone. It was the second deadliest of the four crashes on the day in terms of both plane and ground casualties, surpassed only by American Airlines Flight 11. Twenty-eight minutes into the flight, the hijackers injured several crew members, forcibly breached the cockpit, and murdered both pilots while forcing anyone who remained to the rear of the aircraft. Lead hijacker Marwan Al-Shehhi, who had trained as a pilot for the purposes of the attacks, was able to usurp the flight controls once the captain and first officer were eliminated. Unlike Flight11, whose transponder was switched off, Flight175's transponder was visible on New York Center's radar, which depicted the aircraft's deviation from its assigned flight path for four minutes before air traffic controllers took notice at 08:51 EDT. Immediately thereafter, they made several unsuccessful attempts to contact the cockpit. In the 21 minutes between the hijacking and the crash, three people aboard made phone calls to family members and colleagues on the ground and relayed information regarding the hijackers as well as casualties suffered by passengers and crew. Al-Shehhi flew the airplane into the South Tower at 09:03, in an attack coordinated with the hijacking of Flight 11, which struck the upper floors of North Tower 17 minutes earlier. News coverage of the crash into the North Tower led to Flight 175's impact being the only one of the four attacks to be televised live around the world. By 09:58, after 55 minutes of burning, the damage done to the South Tower by the crash and subsequent fire resulted in it being the first of the Twin Towers to collapse, killing everyone still inside the tower as it fell. During the recovery effort at the World Trade Center site, workers uncovered and identified remains from some Flight175 victims, but many victims have not been identified. Background Attacks The flight was hijacked as part