One ski patroller was seriously injured and another hurt after an avalanche occurred during early-morning mitigation work at Mammoth Mountain on Friday, officials said.

According to the resort, Mammoth Mountain Ski Patrol was conducting avalanche mitigation on Lincoln Mountain around 7:30 a.m. — before ski area operations began — when a slide occurred. Two patrollers were caught in the avalanche.

Both were transported to Mammoth Hospital. One patroller sustained serious injuries and is being transported out of the area for further medical care. The second patroller is being evaluated for possible broken bones, officials said.

The avalanche occurred on Lincoln Mountain following an intense winter storm that dumped more than five feet of snow on the resort since Dec. 23.

As a result of the incident and conditions on the mountain, Mammoth Mountain announced the ski area will be closed for the remainder of the day.

The incident comes as Mammoth Mountain faces intense winter conditions, with powder snow, a 44-inch base at Main Lodge and heavy snowfall in the forecast. Weather officials warn of up to 18 inches of additional snow, strong winds with gusts up to 55 mph, freezing fog and a 90% chance of precipitation.