Chopper 6 was over the scene in Exton, Pennsylvania, along the 1500 block of South Whitford Road.
The crash happened just before 1:30 p.m.
Authorities say the railroad bridge will be closed for an extended period of time. It is unclear how long that will last.
No injuries were reported.
First responders are still trying to determine the extent of the damage to the bridge.
There is no word yet on what may have led to this collision.