On March 11, a powerful earthquake set off a tsunami that swamped the Fukushima Daiichi nuclear plant, cutting off power and causing nuclear fuel rods to overheat and melt. Explosions damaged containment housing and released radioactive particles, and contaminated seawater has flowed into the ocean. Workers are attempting to control the mess, but high radiation levels permeate the plant, making the task difficult and slow.

If you haven't kept up with the rapidly changing events over the past few weeks, no worries: our friends at Nature produced this short explanatory video summing up the crisis, which includes footage from inside the reactor units taken by robots. (Scientific American is part of Nature Publishing Group.) Geoff Brumfiel, who has followed developments from the start, narrates the video, which was produced by Charlotte Stoddard.