Three Mile Island, the home of the worst commercial nuclear accident on U.S. soil, will be closing its doors in 2019. The owner of the plant, Exelon Corp., announced on Monday that they failed to auction off the Pennsylvanian-based nuclear plant, which has seen losses for five straight years. "Today is a difficult day, not just for the 675 talented men and women who have dedicated themselves to operating Three Mile Island safely and reliably every day, but also for their families, the communities and customers who depend on this plant to produce clean energy and support local jobs," The Three Mile accident occurred in 1979 when mechanical failures and human error led to a partial meltdown of one of the plant's two cores, nearly letting 20 tons of radioactive uranium loose.