An 18-year-old motorcyclist killed early today on Likelike Highway was O'ahu's fifth traffic fatality in 10 days.

The victim of the 3:07 a.m. crash was pronounced dead at the scene. The Honolulu Medical Examiner's office was awaiting positive confirmation of identity before releasing the man's name.

Police vehicular homicide investigator Sgt. John Agno said the man was headed south on Likelike Highway when he lost control of his 1992 Honda motorcycle at a bend in the roadway, 154 feet north of the H-1 Freeway and Kalihi Street split.

The motorcycle struck the right guardrail and the operator slid several feet on the guardrail before being ejected, Agno said. The man, who was not wearing a helmet, suffered apparent internal, right arm, head, torso and leg injuries, according to police.

He was pronounced dead by city Emergency Medical Services personnel at 3:37 a.m.

Speed appears to be a factor, police said.

Since June 5, three elderly pedestrians — two men, both 79, and an 84-year-old woman — and two motorcyclist have been killed on O'ahu roadways, raising the island's fatality count to 22 for 2008. By comparison, O'ahu had 36 traffic deaths on this date in 2007, 12 of them pedestrians.