An 8-year-old boy was taken to The Queen's Medical Center in critical condition Saturday night after a one-vehicle accident near Kamehameha and Kalanianaole highways that involved speed and alcohol, police said.

According to a police report:

A 1986 Toyota pickup truck with a 32-year-old man, the boy and a 7-year-old girl in the cab was speeding northeast on Kalanianaole Highway at 10:15 p.m. passing other vehicles.

About a half-mile past the intersection with Kamehameha Highway, the truck went out of control, struck a guard rail on the right shoulder of the road, and rolled over twice. The children may have been ejected from the truck, police said.

After being treated at Castle Medical Center, the man was arrested on suspicion of negligent injury and driving under the influence of an intoxicant.

The boy was taken to Queen's in critical condition; the girl was in Queen's in serious condition.

An investigation is under way.