Train cars seen hanging off overpass in Houston after large derailment

HOUSTON, Texas (KTRK) -- -- Crews and emergency personnel have responded to a large train derailment in northwest Houston on Friday morning.

Houston ABC station KTRK SkyEye13 chopper flew over the scene where 11 train cars were seen off the tracks, with at least two cars seen hanging over a ground-level overpass.

Officials have confirmed that the surrounding roadways are closed as crews work to upright the cars.

It is unclear how long the cleanup will take.

As of now, it is also unclear what led to the derailment or what is inside of the train cars.

This is a developing story and will be updated as more information becomes available.