The medical examiner's office today identified the victim as Curtis Cabral. He was pronounced dead at the scene of the 2:26 a.m. collision. His passenger, 46, was taken to The Queen's Medical Center in critical condition but has since improved to serious condition, police said.

An 18-year-old Wai'anae man was arrested on suspicion of driving under the influence of an intoxicant, and was released without being charged. The accident is being investigated as a negligent-homicide case.

"Speed and alcohol are suspected in this collision," said investigator Sgt. John Agno.

According to police, the teen was driving south on Farrington Highway in a Toyota Corolla when he rear-ended the Harley-Davidson motorcycle. The riders were thrown from the motorcycle.