GRAHAM — The Washington State Patrol is investigating a three-vehicle crash involving a medic aid unit in the Pierce County city of Graham.

KOMO-TV reported that five people, including some firefighters, were taken to the hospital. Graham Fire and Rescue says the firefighters have been treated and released. The others have minor injuries.

Graham Fire and Rescue says the medic unit was headed to a house fire Saturday morning when the medic truck was hit head on.

Troopers said a pickup truck rear-ended a car, causing it to cross over into oncoming traffic and colliding with the medic truck.

Fire crews put out the fire at an abandoned home. Investigators say the cause is suspicious.