Train derails on bridge over Schuylkill River in University City

A CSX train carrying crude oil and sand derailed on a bridge over the Schuylkill River in University City overnight.

The Coast Guard said the incident happened at about 1 a.m. on the Schuylkill Arsenal Bridge, which crosses over the river from University City to Grays Ferry south of the South Street Bridge.

The two-locomotive, 101-freight-car train was traveling from Chicago to Philadelphia, according to CSX. Seven freight cars -- six containing crude oil and one containing sand -- derailed, the company said.

There's no indication any materials are leaking from the derailed cars, the Coast Guard said.

A Coast Guard crew is monitoring the derailment, and pollution responders are also at the scene.

It wasn't immediately known what caused the train to derail. Officials are working to clear the derailement "in a way that is safe and environmentally responsible," a CSX statement said.

The incident disrupted travel overnight on the Schuylkill Expressway, but traffic was moving again early this morning.