SMITHFIELD, Maine (AP) — Authorities in Maine say a 53-year-old man was killed when his snowmobile a struck a tree.

The Maine Warden Service says Brian Gatie, of Smithfield, was operating the first of three sleds traveling together when he crashed on Saturday. Game wardens say he wasn't wearing a helmet and excessive speed appears to be a factor in the crash.

It was the third fatal snowmobile crash this year.

An investigation is continuing.