LOMA, Colo. — Two people aboard a helicopter-like aircraft were killed when it crashed into a river in western Colorado, but no one on the ground was injured, authorities said Sunday.

The gyroplane went into the Colorado River shortly after 6 p.m. Saturday, the Mesa County Sheriff’s Department said.

The sheriff’s department said both victims were adults. Their names weren’t immediately released. Autopsies were planned.

The sheriff’s department said no one else was on board.

Federal Aviation Administration spokesman Allen Kenitzer said the aircraft was a Xenon gyroplane. Gyroplanes look like helicopters but are powered by propellers. Air flow created by the aircraft’s forward motion spins the rotors, which provide lift.

The FAA and the National Transportation Board are investigating.

Witness Ron Jenkins said he and another man were fishing on the bank of the Colorado River when the gyroplane crashed nearby.

It began to fishtail and sparks were flying from it before it crashed nose-first in shallow water, he told the Grand Junction Daily Sentinel.

Jenkins said he and the other angler hurried to their boat, went downriver to the gyroplane and then waded to it. They were able to remove one victim by cutting a seat belt, he said.

The sheriff’s department said the crash disrupted electric service to some areas, but no details were available. Grand Valley Power said service had been restored by Sunday morning.