A father and his 10-year-old son were killed in a snowmobile crash in Maine early Sunday, authorities said.

Jason Tracy, 33, of Hermon, and his son, whose name was not immediately released, were killed when their snowmobile struck a tree on the edge of a field in Hermon at about 1 a.m. Sunday, the Bangor Daily News reports, citing a news release by the Maine Warden Service.

Warden Lt. Dan Scott said speed and alcohol were factors in the crash, which remains under investigation.

Tracy’s son was wearing a helmet at the time of the crash, but Tracy was not, according to the agency.

Calls seeking additional comment on Monday were not immediately returned.