Police and fire crews were called shortly before 8 a.m. to the westbound lanes of the H-1, about a quarter-mile before the H-2 off-ramp, where six vehicles had collided. Police were still investigating the cause of the accident this morning, but fire officials said the fuel tank on a container truck appeared to have been punctured in the chain-reaction collision, which also involved a cement mixer and another truck.

A 31-year-old woman and two men, 52 and 46, were taken to The Queen's Medical Center. The woman and the younger man was listed in guarded condition, a hospital spokeswoman said, and a condition report was not available for the older man. Fire department spokesman Capt. Richard Soo said that a third man was taken to St. Francis Medical Center-West, but a hospital staffer could not confirm that. Two other people refused treatment at the scene, Soo said.

Fire crews brought in absorbent material to mop up the 40-50 gallons of diesel, which also dripped through the viaduct to a business parking area below.

The westbound lanes were closed, with traffic rerouted through the mauka shoulder lane.