A dog died and several people were injured when lightning struck about 500 feet below the summit of Mount Bierstadt on Sunday morning, the Clear Creek County Sheriff’s Office said.

The lightning struck at about 11:30 a.m., said Undersheriff Bruce Snelling. Initial reports said up to 16 people were injured and one dog was killed, he said. As of 5 p.m., all hikers were accounted for and off the mountain.

Emergency medical personnel transported eight adults from the trailhead, and three were taken to local hospitals.

One person suffered serious injuries and two suffered injuries that are not considered life-threatening, according to a sheriff’s office news release.

Five other people refused further treatment, the release said.

As many as 100 people may have been on the mountain when the accident happened, Snelling said. “It is a popular destination because it is one of the fourteeners you can walk.”

The sheriff’s office, Alpine Rescue Team, Summit County Search and Rescue and other emergency units were involved in the evacuation.