Honolulu police are still investigating a collision between a motorcyclist and bus that left a 43-year-old man in critical condition.

The crash occurred at about 6 p.m. Saturday, according to police, on Salt Lake Boulevard near the main entrance to Aloha Stadium.

Police said the motorcyclist was reported to be traveling westbound on Salt Lake Boulevard, and that he disregarded a red traffic signal and collided with a bus traveling northbound. A 64-year-old man, the bus operator, was not injured in the collision.

The motorcyclist was taken to the hospital in serious condition, where he deteriorated and was later listed in critical condition. He was wearing a helmet at the time of the collision.

Police said at this time, speed appears to be a contributing factor in this collision.

It is the fourth motorcycle crash police have reported in the past three weeks resulting in motorcyclists in critical condition.