'Don't touch anything', mayor pleadspublished at 14:56 Greenwich Mean Time
We're now hearing that the news conference has been delayed.
So we'll bring you an important message that Philadelphia's mayor had for city residents when she spoke last night:
"If you see debris, call 911, don't touch anything," Cherelle Parker said.
The exclusion zone around the crash site is large, however there could still be debris found further out.