plant transformed the rapids into waterfalls. On June 22, 1895, the world's then-largest irrigation canal, the Great Feeder (located 5 miles northeast of Ririe), began diverting water from the Snake River, helping to convert tens of thousands of more acres of desert into green farmland. The area grew sugar beets, potatoes, peas, grains, and alfalfa, and became one of the most productive agricultural regions of the United States. The city once again began to flourish, growing continuously into the 20th century. Nuclear reactors In 1949, the Atomic Energy Commission opened the National Reactor Testing Station (NRTS) in the desert west of Idaho Falls. On December 20, 1951, a nuclear reactor there produced useful electricity for the first time in history. There have been more than 50 unique reactors built at the facility for testing—only three remain active. On January 3, 1961, NRTS became the scene of the only fatal nuclear reactor incident in U.S. history. The event occurred at an experimental U.S. Army plant known as the Argonne Low-Power Reactor, which the Army called the Stationary Low-Power Reactor Number One (SL-1). Due to poor design and maintenance procedures, a single control rod was manually pulled out too far from the reactor, causing the reactor to become prompt critical, leading to a destructive power excursion. Three trained military men had been working inside the reactor room when a mistake was made while reattaching a control rod to its motor assembly. With the central control rod nearly fully extended, the nuclear reactor rated at 3 MW rapidly increased power to 20 GW. This rapidly boiled the water inside the core. As the steam expanded, a pressure wave of water forcefully struck the top of the reactor vessel, upon which two of the men stood. The explosion was so severe that the reactor vessel was propelled nine feet into the air, striking the ceiling before settling back into its original position. One man was impaled by a shield plug and lodged into the ceiling, where he died instantly. The other men died from their injuries within hours. The three men were buried in lead coffins, and that entire section of the site was buried. The core meltdown caused no damage to the area, although some radioactive nuclear fission products were released into the atmosphere. The site has since developed into the Idaho National Laboratory (INL), a national laboratory operated by the United States