Philadelphia, Feb. 1 -- A medical jet with six Mexican nationals onboard crashed into a busy Philadelphia neighborhood Friday (January 31), authorities said, marking another US aviation disaster after a passenger aircraft and a military helicopter collided midair in Washington earlier this week.

The aircraft, which the Federal Aviation Administration said was a Learjet 55 executive aircraft, crashed around 2330 GMT into the densely-populated district of the city, packed with homes, shops and busy roads.

It was bound for Springfield-Branson National Airport in Missouri, and had taken off from Northeast Philadelphia Airport, the FAA said in a statement confirming that it would investigate along with the National Transportation Safety Boar...