SULPHURDALE, Beaver County — A man was in critical condition Sunday after a semitrailer rollover on I-15 in Beaver County.

Officials believe the driver of the semitrailer fell asleep at the wheel while driving south on I-15 at approximately 3:30 p.m. The driver awoke as the vehicle drifted off the roadway and over-corrected, rolling the semitrailer onto its side and blocking both southbound lanes of traffic.

The driver was traveling with another man who was partially ejected from the vehicle. He was flown to a hospital in critical condition, officials said.

Traffic was rerouted around the accident for approximately three and a half hours.