Honolulu police investigate the scene of a fatal two-car accident at an H-2 on-ramp from Kamehameha Highway. Witnesses told police the cars were speeding. Richard Ambo • The Honolulu Advertiser

Police blocked H-2 northbound onramps for six hours while they investigated the accident, which occured just after 3 a.m. just before the ramp leads into the freeway's northbound lanes.

"We have unconfirmed reports that there was some kind of speed contest," said Maj. Robert Prasser of the police traffic division.

Prasser said that the cars, one blue and one black Honda, were modified, racing-type vehicles that witnesses said were headed side-by-side in the northbound lanes.

It's unclear whether the cars made contact with each other but they ended up on opposite sides of the roadway, he said.

The 23-year-old man killed in the accident, the 40th fatality recorded this year, was the driver of the blue Honda. He was ejected from one of the cars on the right shoulder of the road, his leg amputated by the crash, and he was declared dead at the scene, Prasser said.

Prasser said the grassy area below the accident was searched before authorities concluded there were no additional bodies.

The first city ambulance was summoned at 3:07 a.m. and two more, one from the city's Emergency Medical Services station in 'Aiea and one from the private American Medical Response station at the airport, were called for backup, said Donald Gates, EMS chief of operations.

The ambulances took the male passenger of the blue Honda, one of the two female passengers and a13-year-old boy who rode in the black Honda to The Queen's Medical Center. A hospital spokeswoman said the male passenger, whose age was unknown, remained in critical condition and the 22-year-old woman was listed in guarded condition.

Fire department spokesman Capt. Richard Soo said the teenager was burned, and police said his condition was listed as guarded.

Two more victims, a 19-year-old female riding in the blue Honda and the17-year-old male driver of the black Honda, were treated at Kaiser Moanalua Medical Center and released, a Kaiser spokeswoman said.