A 20-year-old woman was killed when she and four other people were thrown from their vehicle after the driver lost control of the car, struck a guard rail and rolled over several times on the H-1 freeway near the Vineyard Boulevard offramp Wednesday night.

Alcohol is believed to have been a factor in the accident that occurred at 9:40 p.m. police said. Authorities haven’t determined if the driver was speeding.

Emergency Medical Services said three males — two 20-year-olds and one 19-year-old — and a woman, 19 — were taken to the hospital in critical condition.

Polices said the male driver, who is from Wahiawa, was traveling east on the H-1 freeway when he lost control of the soft-top Jeep, struck a guard rail on the south side of the road and then rolled over several times. The driver and his four passengers were ejected from the vehicle. The accident occurred a mile east of the Vineyard Boulevard offramp.

This was Oahu’s 31st traffic death, compared to 30 at the same time a year ago.

H-1 eastbound was closed until about 1:15 a.m. at the Vineyard Boulevard exit as officers investigated the accident, Honolulu police said.