Ski patrollers from mountain resorts in California, Nevada, and Colorado are at Mammoth Mountain in the Eastern Sierras, helping to provide safety following an avalanche that caught two patrollers and left one critically injured.

Mammoth Mountain officials said the slide occurred during avalanche mitigation work following a significant Sierra Nevada snowstorm, during which about six feet of snow fell in 36 hours.

Two ski patrol staff at Mammoth Mountain were caught in an avalanche while doing mitigation work after an atmospheric river dropped about six feet of snow in 36 hours, Mammoth Mountain officials said.