Honolulu paramedics administered advanced life support to two bicyclists Tuesday who were involved in vehicle collisions.

The Honolulu Emergency Medical Services reported treating a 37-year-old man on a bicycle who was hit by a vehicle in the Mokuleia area on Farrington Highway Tuesday evening.

At around 6:45 p.m. a 19-year-old man reportedly struck the 37-year-old man while trying to pass another vehicle in his Toyota truck. The bicyclist, who was not wearing a helmet, was taken to a trauma hospital in critical condition. The driver of the truck sustained minor injuries after the vehicle rolled over, but he declined transportation to a hospital.

Drugs, alcohol and speed did not appear to be factors, the Honolulu Police Department said in a news release. An investigation is ongoing.

Earlier in the day a 50-year-old bicyclist died after running into a flatbed truck in Kailua.

The 31-year-old truck driver, who was heading north on Mokapu Boulevard, made a right turn onto Kapaa Quarry Road when the bicyclist, traveling on the road’s paved shoulder, hit the truck’s rear and ejected onto the pavement. The bicyclist, who was wearing a helmet, succumbed to his injuries at a nearby hospital.

Drugs, alcohol and speed did not appear to contribute to the collision, but an investigation remains ongoing, police said.

This is the fourth reported traffic fatality on Oahu this year, the same amount this time last year, police said.