"Three days after an explosion on an oil rig off the southeast coast of Louisiana, an environmental disaster has been at least temporarily forestalled, but the search for 11 missing workers has ended, the Coast Guard said Friday evening. Explosions on Tuesday night and Thursday sank the giant rig that had been atop a well reaching thousands of feet underwater. The first blast left 11 workers unaccounted for and a sheen of oil spread across marine-rich waters in the Gulf of Mexico. Now it appears clear that those workers will not be found alive. “We have just made a very difficult decision,” Rear Adm. Mary E. Landry, commander of the Eighth Coast Guard District, said at a news conference. “After a three-day search covering 5,300 miles, we have reached a point where reasonable expectations of survival have passed.” "