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Oil rig explosion

This aerial photograph shows damage from an explosion and fire on an oil rig in the Gulf of Mexico, about 25 miles southeast of Grand Isle, La., Friday, Nov. 16, 2012. Four people were transported to a hospital with critical burns and two were missing. (AP Photo/Gerald Herbert)

Gulf oil rig blast

Ships and helicopters

are searching for two oil rig workers who disappeared when an explosion

rocked a gulf oil rig off the coast of Louisiana and set it on fire, Coast Guard officials said, Nov. 16.