Two people were swept under the ice on the Big Susitna River on Thursday morning while three others were able to reach safety, Alaska State Troopers said.

A window of cold and clear weather has drawn hundreds of people to skate, bike and walk on the lake ice in recent days.

Tom McGuire, a 79-year-old Haines author and backcountry adventurer, fell through the ice while skating alone on Chilkoot Lake, triggering an extensive search by local volunteers and state officials.