[Note: A version of this distributed by email had the wrong title. Apologies!]
40 years ago, on March 28, 1979, Three Mile Island (TMI) Unit 2 nuclear power plant melted down and experienced a hydrogen explosion. (Unit 1 has continued to run all these years but likely will be shut down soon as it loses a lot of money for the owners.)
Days afterwards: “Governor Thornburgh advised pregnant women and pre-school age children to leave the area within a five-mile radius of the Three Mile Island facility until further notice. This led to the panic the governor had hoped to avoid; within days, more than 100,000 people had fled surrounding towns.”
The cause was a combination of equipment failures, design defects, and operator errors.