There was an explosion this morning on the Vermilion Oil Rig 380, 80 miles south of Vermilion Bay along the central Louisiana coast, west of the site of the Deep Water Horizon blast. 13 workers were rescued by the Coast Guard, with only one seriously injured. The rig is owned by Houston-based Mariner Energy, and it's unclear whether it was a drilling rig or production platform. [CNN, NPR]

Update: Excellent news! A mile-long oil sheen is spreading from the site of the explosion. [AP/SF Gate]