A 64-year-old Kahului man has died in a motorcycle crash in Haiku.

He has been identified as Dean Line Sr.

At about 6:10 p.m. Monday, police said a black 2017 Harley Davidson motorcycle operated by Line was traveling north on West Kuiaha Road when it drifted onto the right shoulder and struck a guardrail.

Line was thrown from his motorcycle upon impact and struck the guardrail.

Police said the motorcycle continued traveling north into the southbound lane before coming to a rest on a grassy shoulder.

Line was pronounced dead at the scene. Police said he was not wearing a helmet at the time of the crash.

It’s unknown at this time whether speed, drugs or alcohol were involved. The investigation is ongoing.

This is Maui County’s 17th traffic-related fatality compared to 23 at the same time last year.