About 30 vehicles slid off the highway or were damaged Tuesday afternoon when a tractor-trailer jackknifed in the southbound lanes of Interstate 95 in Etna.

The pileup in Penobscot County was caused by a change in weather conditions exacerbated by a sudden, intense snow squall that created whiteout conditions, Maine Department of Transportation spokesman Ted Talbot said.

“The snow continued to fall and when the temperatures dropped the road conditions changed for the worse,” he said.

The truck jackknifed just after 1 p.m. and drivers of cars that tried to avoid the wreck began to slide, with most ending up off the road.

Steve McCausland, spokesman for the Maine Department of Public Safety, said two people suffered minor injuries.

“The sudden storm caught a lot of drivers off guard,” he said. “Fortunately, most of the damage was caused by slideoffs.”

A portion of the tractor-trailer blocked the highway and reduced traffic to one lane for two hours after the crash, but Maine State Police then shut down both southbound lanes for 3½ hours so crews could clean up the mess and tow cars. They were reopened around 6:30 p.m.

McCausland said Tuesday’s accident was nowhere near as severe as the Feb. 25, 2015, crash that caused a 75-vehicle pileup near that same stretch of road. The 2015 chain-reaction collision was believed to be the worst in Maine history. Seventeen people were transported to area hospitals and 50 vehicles had to be towed from the scene.

Police had to shut down the northbound lanes of I-95, between Etna and Carmel, for five hours in 2015. One state trooper at the scene described the crash site as a “giant pile of metal.”

Talbot said that stretch of I-95, which is mostly rural, has had more than its share of accidents, especially during the winter months.

“It has seen some weird weather patterns, the type of weather that only occurs in open, rural areas like Etna,” Talbot said.