AUBURN - A 47-year-old Chester man was airlifted to a Boston hospital Monday night after he rolled his truck on Route 121 (Chester Road), police said.

William Johnston was in the intensive care unit Tuesday morning at Beth Israel Deaconess Medical Center, according to Sgt. Chip Chabot.

The accident happened just before 9:30 p.m. near 278 Chester Road. Johnston was traveling south when he lost control of his GMC 2500 series truck, which rolled over.

Johnston was thrown from the truck and emergency workers found him lying in the road suffering from serious head and upper body trauma, according to Fire Chief Bruce Phillips.

A Dartmouth-Hitchcock Advance Response Team helicopter landed at the Auburn Village School to take Johnston to the Boston hospital.

Chabot said the crash remains under investigation, and police are trying to determine if speed was a factor.