Two O'ahu men were killed in separate crashes about an hour apart on Thursday night.

In the first crash, a 29-year-old man died after he lost control of his motorcycle and struck a road sign. The city medical examiner's office identified the victim as Daniel Kapu of Hau'ula.

Police said Kapu was driving north on Kamehameha Highway when he lost control of his 2006 Kawasaki Ninja motorcycle and crashed into a road sign south of Punalu'u Valley Road. Kapu was pronounced dead at the scene of the 9:52 p.m. crash.

Police said speed may have been a factor and that Kapu was not wearing a helmet.

At about 10:55 p.m., in Whitmore Village, a moped rider was struck and killed by a sport utility vehicle. That man was identified as Adrian Corales, 29, of Kahuku.

Police said Corales was driving west on Whitmore Avenue when he disregarded a stop sign and was struck broadside by the SUV near the intersection with 'Ihi'ihi Avenue. Corales was taken to The Queen's Medical Center, where he died.

Corales also was not wearing a helmet, police said.

The occupants of the SUV — a 39-year-old woman, an 11-year-old boy and a 5-year-old girl — were not injured, police said.

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

Meanwhile, Las Vegas officials have identified a Honolulu man killed in a single-car crash there on Thursday as Jashua Choy.

Police said Choy, 41, was driving a 2010 Suzuki SX4 west of Las Vegas Boulevard about 2:40 a.m. when the SUV hit a palm tree.