A multi-vehicle crash early Sunday on the H-1 freeway in Aiea left a 19-year-old motorcyclist in critical condition, according to the Honolulu Police Department.

The incident occurred around 12:30 a.m. when the 19-year-old motorcyclist, traveling eastbound on H-1, rear-ended a 23-year-old motorcyclist. Both riders were thrown onto the roadway upon impact, police said.

A 20-year-old driver stopped near the scene to assist, but an unidentified motorist, also traveling eastbound, struck the 19-year-old motorcyclist and his motorcycle. The force of this secondary collision caused the motorcycle to crash into the stopped vehicle, according to police.

The driver who hit the motorcyclist briefly stopped before continuing eastbound without providing aid or information, police said.

A 20-year-old female passenger on a motorcycle was also struck by debris from the second collision.

The 19-year-old motorcyclist was transported to a nearby hospital by emergency services in critical condition. The 23-year-old motorcyclist and the 20-year-old female passenger were both taken to a hospital in good condition by private vehicle. The 20-year-old driver who stopped to help and his two passengers were not injured, police said.

The 19-year-old was wearing a helmet at the time of the crash.

Police believe speed was a factor in the collision, though it is unclear whether drugs or alcohol played a role. The investigation is ongoing.