Waterford — A man performing tree work off Interstate 395 sustained a serious neck injury from his chain saw Friday, state Department of Transportation officials said.

The unidentified man, who works for Asplundh, which is contracted by the state DOT for tree trimming, was treated at the scene by responding emergency medical personnel and flown by Life Star helicopter to Hartford Hospital. His condition is unknown.

State police closed both sides of the highway in the area of Exit 77 to allow the medical helicopter to land. The accident was reported shortly before 11 a.m. State Police Lt. J. Paul Vance said the incident appears to be "purely accidental."