As of Saturday morning, officials confirmed seven dead — six on the jet, one person on the ground — and 19 injured.

Recovery crews and divers searched the Potomac River for remains and cleared wreckage Saturday from the midair collision of a passenger jet and Army helicopter that killed 67 people.

Here are some of the reasons why aircraft can catastrophically veer toward the ground like a medevac jet did in Philadelphia on Friday night.

The collision on Wednesday night, between an army Black Hawk helicopter and a commercial plane, left no survivors.