Two people were seriously injured in a one-vehicle crash on I-395 in Bangor on Friday about 8:45 p.m., causing traffic to be closed for over 2 hours.

A preliminary investigation by the Maine State Police indicates that Devon Ireland, 23, of Bangor, was westbound on I-395 when he failed to negotiate a turn and lost control of the vehicle.

“The car went over the guardrail and came to rest upside down across both eastbound lanes of travel,” the department said in a news release Saturday morning.

Lauren McCann, 23, of Bangor, “does not appear to have been wearing a seatbelt,” and was ejected from the vehicle, according to the release.

Ireland suffered “significant” injuries while McCann sustained “life-threatening” injuries as a result of the crash. Both were taken to Eastern Maine Medical Center.

“Speed and alcohol are believed to be contributing factors,” the department said.

The crash remains under investigation.