All three firefighters responded to the World Trade Center on September 11 , 2001 . There were some additional 863 cancer cases among both fire and EMS personnel , according to FDNY , which keeps a separate database for its members . They were killed in a terrorist attack that was carried out by Osama bin Laden and his Al Qaeda associates who had hijacked four commercial airplanes with passengers and crew members aboard. Hundreds of firefighters and ambulance workers suffer from respiratory illnesses .
All three firefighters responded to the World Trade Center on September 11 , 2001 . They were killed in a terrorist attack that was carried out by Osama bin Laden and his Al Qaeda associates who had hijacked four commercial airplanes with passengers and crew members aboard. Hundreds of firefighters and ambulance workers suffer from respiratory illnesses .