The slides come near the end of an avalanche season experts say is notable both for its heightened danger and lack of deaths.

Anchorage municipal officials say at least 16 roofs have buckled in the city this winter under heavy snow and ice, and they’re wary of additional collapses after another storm dropped more snow this weekend.

The reason for the uptick in human-triggered avalanches this winter: persistent weak layers in the snowpack.

The roof collapsed at a South Anchorage gym during a fitness competition. The Anchorage Office of Emergency Management cautioned residents that the city has had near-record snow conditions this winter, and residents should consider the snow load on their roofs. Officials also warned that property owners should exercise extreme caution if removing snow from their roofs themselves.