The Pennsylvania Department of Transportation (PennDOT) says that heavy rain and a clogged pipe are responsible for flooding that left drivers stranded for hours on Schuylkill Expressway (I-76) in Montgomery County on Monday.

Flood waters forced transportation officials to close down eastbound I-76 from I-476 to Gladwyne for close to 10 hours yesterday. The road closure left some drivers stranded for six hours, according to NBC Philadelphia.

No injuries were reported, but many drivers had to be rescued from stalled vehicles.

PennDOT was able to reopen a single lane of eastbound I-76 by 10 a.m. Both lanes were reopened by 2 p.m.

PennDOT later said that the rain combined with a clogged pipe were to blame for the interstate flooding. As many as five inches of rain were reported in the area. “It appears to be a cross pipe across the 76 expressway that was clogged up. Which then clogged up the inlet which clogged up the shoulder, and the right travel lane with water,” said PennDOT spokesman Brad Rudolph.

Flooding was also reported on I-95 in Philadelphia and Route 38 in Cherry Hill.

Transportation officials warn drivers to never attempt to drive through flood waters.