Separate vehicle crashes about an hour apart last night claimed the lives of two Oahu men.

Shortly before 10 p.m., a 29-year-old Hauula man was killed when he lost control of his motorcycle in Punaluu and struck a road sign.

At about 11, a 29-year-old Kahuku man died after the moped he was operating in Wahiawa ran a stop sign, entered an intersection and was broadsided by a sport utility vehicle.

The deaths were the 27th and 28th traffic fatalities of the year, compared with 26 at this time last year.

Police Lt. David Nilsen said the moped rider was on Nani Ihi Avenue and had entered Whitmore Avenue when he was hit.

He said the moped operator was not wearing a helmet.

Bryan Cheplic of the city's Emergency Services Department said paramedics treated the man at the scene, then took him to a trauma center in critical condition. Cheplic said the man died shortly afterward.

Nilsen said the occupants of the SUV — a 30-year-old woman, 11-year-old boy and 5-year-old girl — were not injured.

Police believe speed may be a factor in the crash. They have yet to determine if alcohol or drugs were involved.

In Punaluu, police said the motorcycle rider was headed north on Kamehameha Highway, near Punaluu Valley Road, when he lost control of his 2006 Kawasaki Ninja and struck a road sign.

Police said the man was not wearing a helmet.

Cheplic said paramedics pronounced the man dead at the scene at 10:33.

Police said speed may have been a factor in the crash. They have not yet determined if alcohol or drugs were involved.

Kamehameha Highway was closed in both directions in the area of Ching Store from about 10:40 p.m. to 1:50 a.m.