Suffolk County police have identified the motorcyclist who sustained serious head injury after crashing Friday night in Elwood as Joseph Alyward, 44, of Greenlawn.
Alyward was going east on Little Plains Road near Hillock Court when he lost control of his 2012 Harley-Davidson Legend and crashed about 6:30 p.m., police said.
"We're trying to determine the cause," said Det. Sgt. James Scimone of the Second Precinct said Friday. "We have no witnesses."
Alyward was wearing a helmet, but hit his head on the curb, police said.
It did not appear another vehicle was involved, Scimone said.
Alyward was airlifted to Stony Brook University Hospital, where he was undergoing tests to determine the extent of his head injuries, police said. He was in critical but stable condition Friday night and was expected to survive, police said.
Detectives ask anyone with information to call 631-854-8252.