DENVER (AP) — Two firefighters were seriously injured in a single-vehicle rollover crash as they were responding to a house fire south of Denver.

The roughly 3,000-gallon water tanker went off a rural road, through a fence and into a field just west of Castle Rock in Douglas County on Tuesday night. The firefighters were airlifted to a Denver-area hospital.

Kim Spuhler, a spokeswoman for South Metro Fire and the Franktown fire department , says the firefighters had to be cut out of the two-person truck, and their recovery is going to be an "uphill battle."

Their names have not been released, but they were listed as non-critical and stable. Investigators have not said what led to the crash. The tanker is attached to Franktown Fire.

Several fire departments were responding to the blaze.