Traffic was backed up for hours Friday on the Maine Turnpike northbound lane from Scarborough to Saco, when a brief rainstorm triggered a series of accidents involving some 15 cars and four tractor-trailers.

According to State Trooper Sgt. Paul Christianson, the initial accident occurred at about 3:40 p.m. The turnpike wasn’t fully cleared until about 9 that night.

Though clearing the roads took hours, no one was seriously injured in the pileup. Traffic was blocked for 10 miles in the northbound lane, and slowed southbound traffic, said Christianson.

“It probably started because the front slowed down because of the shower,” said Christianson. “Then people behind them either weren’t paying attention or didn’t have the proper following distance.”