PORTLAND, Ore. (KOIN) — An ambulance was involved in crash with another vehicle, leaving two EMS staffers and the vehicle occupants injured Saturday morning, authorities say.

Just before 4:45 a.m., an Adventist Health Tillamook Emergency Medical Services ambulance collided head-on with the other vehicle at milepost 26 on Highway 6. Adventist reports the occupants were returning to Tillamook from a patient transfer earlier in the morning.

The ambulance overturned in the accident and the two EMS staff were able to get themselves out, receiving only minor injuries. Then they helped the occupants in the other vehicle, who were later taken by ambulance to Legacy Emanuel Medical Center in Portland.

Officials from the Banks Fire District were also on scene to provide aid.

EMS officials on the scene said they’ve initially determined the accident was caused by fallen road debris from a storm, although Oregon State Police and Adventist Health Tillamook are continuing the investigation.