The Hawaii County Police Department on Tuesday identified the 21-year-old woman who died in a two-vehicle collision Saturday as Sarah Akiona of Waimea.

Akiona was the front-seat passenger in a Honda sport utility vehicle that crossed the centerline of Highway 19 before colliding with a Hawaii Gas propane tanker truck, police said. The impact flipped the tanker, filled with roughly 1,750 gallons of liquid propane, which caused a fire from a broken pipe on the vehicle to burn for two days as firefighters shot more than a million gallons of water onto the truck to prevent a catastrophic explosion.

The fire on the propane tanker was extinguished Monday morning after firefighters sprayed the tanker with enough water to nearly fill two Olympic-size swimming pools.

“We are saddened by the loss of life, and our hearts go out to those affected by this tragic accident,” said Alan Tang, spokesman for Hawaii Gas.

The driver of the Hawaii Gas tanker truck, a 54-year-old Hilo man, was transported by paramedics to the Hilo Medical Center in stable condition.

The driver of the 2004 Honda SUV was a 23-year-old Waimea man. The other passenger was a 3-year-old boy who was buckled up in a car seat. Both were treated at the scene Saturday.

Police said Tuesday they do not think excessive speed or alcohol were factors in the collision.

Tang said the gas utility is also conducting an investigation.

Tang said the driver was returning to the Hawaii Gas base yard in Hilo after delivering propane to customers. Tanker trucks are used to service all of Hawaii Gas’ customers on the neighbor islands. Most of Hawaii Gas’ customers on Oahu are serviced by the utility’s pipeline.