Residents of Alaska's capital, Juneau, are undergoing an emergency evacuation as of Monday due to major flooding, which began due to a glacier lake outburst flood. This is a situation when a dam containing a glacial lake — in this case the Suicide Basin, a side basin on the Mendenhall Glacier — suffers a breach. The break in Suicide Basin was so significant that the subsequent flood has washed away and severely damaged homes all along the Mendenhall River.
According to FEMA, there was a less than 1 percent chance of "extreme" flooding like this occurring in that region of Alaska. "We didn't even think that this was possible," National Weather Service Juneau hydrologist Aaron Jacobs told ABC News.
