Just for those who aren't familiar with the area there, whatever happened they only lasted 30 seconds after takeoff so it was a major malfunction. Had they had another minute the Delaware River is right there to their left underneath them, all they would have to do is just steer the plane towards the river and crash there, that's what most Pilots would have done over a heavily populated area. They didn't have time for that. Weight proportions could have been off and the nose of the plane went up and they had a stall, as has been suggested there could have been a structural malfunction like the loss of a wing, unfortunately the plane is in tiny little pieces that are scattered all over Northeast Philadelphia.
Hopefully people who find small pieces will contact the NTSB, I think it's
Witness@ntsb.com or it used to be but frankly just call 911 and you will have a radio car at your door very quickly to collect what you have.