SHOREVIEW, Minn. (AP) -- Authorities in a Twin Cities suburb say a bystander came to the rescue of a teenage girl who caught on fire at a gasoline pump.

Shoreview Fire Chief Tim Boehlke says the bystander used an extinguisher to douse the flames on the 17-year-old after she ran into the Quik Stop store Tuesday morning.

Boehlke says the fire began while the girl was with her vehicle at one of the pumping stations. He says investigations don't know what caused the fire.

The bystander also put out the flames near the pumps before fire crews arrived. The fire chief says authorities have not been able to identify the bystander.

The girl was being treated for life-threatening injuries at Regions Hospital in St. Paul. Her name was not disclosed.