Officials say new sandbag-style barriers installed along a river in Juneau, Alaska’s capital, have held back record levels of flooding and prevented widespread damage after an ice dam at the nearby Mendenhall Glacier released a massive amount of rainwater and snowmelt downstream.

This year, a giant wall of reinforced sandbags erected with the help of the U.S. Army Corps of Engineers held back the worst of the flooding in Juneau, to residents' great relief.

Glacial outburst floods aren't a new phenomenon in Alaska, but climate change is scrambling the geography of risk.

The all clear has been given and residents have been allowed to return to their homes in Alaska’s capital of Juneau after a glacial lake outburst sent debris-filled water rushing down the Mendenhall River on Tuesday night and Wednesday morning.

A glacial lake outburst flood in the Sikkim Himalayas in October 2023 damaged more than 30 bridges and destroyed a 200-foot-high (60 meters) hydropower plant. Residents had little warning. By the time the disaster was over, more than 50 people had died. Avalanches, rockfalls and slope failures can also trigger glacial lake outburst floods.

An overflowing glacial lake caused a surge in the Mendenhall River on Wednesday, prompting flood alerts and evacuations in Juneau.

At least three people have died after heavy rain and flash flooding lashed Chattanooga, Tennessee, overnight Tuesday and shut down interstates, stranded cars and prompted swift water rescues