All roads running through the Valley Forge National Historical Park were closed Tuesday after a sewer main break caused extensive flooding. Some reports estimated the volume of spilled raw sewage to be about 5 million gallons.

Tredyffrin Township officials said the break appeared to have occurred around 10:30 a.m. in a pipe section of the Valley Creek Trunk Sewer Force Main near the intersection of Routes 252 and 23 in Upper Merion Township.

The spill drew a multi-agency response that also included contractors and environmental and engineering consultants, according to authorities. Officials said in a release that repairing the main "will require extensive damage assessment and traffic control."

An initial radio report indicated about 5 million gallons of raw sewage spilled into the Valley Creek. Neither township nor state officials immediately returned requests for comment Tuesday evening.

It wasn't clear when the roads cutting through Valley Forge would be reopened. The closures included:

- Route 23 eastbound from Davis Road to Rt 252

- Route 23 westbound from N. Gulph Rd to Rt 252

- Route 252 northbound from the PA Turnpike

- North and South Outer Line Drives

- Gulph Rd from Thomas Rd to Rt 23

- Yellow Springs Rd. at the Covered Bridge