ANCHORAGE, Alaska — A steering problem may have preceded a boating accident in which four people, including a Colorado man, were ejected into Alaska’s Kenai River.

A search continues for 63-year-old Phillip Keltner, who was last seen floating downriver.

Keltner’s hometown was not immediately available.

The four people on board were not wearing life jackets when the accident occurred Friday night, Alaska State Troopers said.

Troopers shortly after 9 p.m. received a report of a boat out of control near Centennial Park.

The boat may have experienced a mechanical issue with a steering cable, said troopers’ spokeswoman Megan Peters in an email response to questions.

She did not have details on how the people on board were ejected. But the boat, a private vessel and not a charter boat with a guide, did not sink.

Soldotna police and other emergency responders joined troopers in an unsuccessful search for Keltner. The Alaska State Park Service continued the search Monday. Keltner’s next-of-kin were notified of the accident.

The cause of the boat malfunction is under investigation.

The Kenai River is Alaska’s most heavily fished river. Rainbow trout and runs of Chinook, sockeye and silver salmon draw thousands of anglers.

The 82-mile (132-kilometer) glacier-fed river starts at Cooper Landing and flows west to Cook Inlet. It is the major river on the Kenai Peninsula south of Anchorage.