The National Transportation Safety Board is investigating the fiery crash, which occurred just two days after a commercial jet and Army helicopter collided at Reagan Washington National Airport, killing 67 people.
Jet Rescue Air Ambulance, which owned the Learjet 55 that crashed near Roosevelt Mall shortly after taking off from Northeast Philadelphia Airport, said six people were aboard the small medical plane: a pilot, copilot, physician, paramedic, pediatric patient and her mother.
All six were Mexican nationals, Mexico President Claudia Sheinbaum said Saturday.
The air ambulance was transporting the pediatric patient from Philadelphia to Tijuana International Airport, with a scheduled fuel stop in Springfield, Missouri, the Federal Aviation Administration said.
NTSB is investigating what caused the plane to plummet less than a minute after takeoff.
Video of the crash showed the plane quickly descending and crashing, causing a large fireball explosion that set several nearby homes, cars and other objects on fire. Philadelphia Fire Commissioner Jeffrey Thompson said firefighters were able to extinguish the fires.
