April 11, 1970: Apollo 13 lifted off from Kennedy Space Center in Florida. NASA’s planned third lunar mission nearly became its most tragic—the first issue came during takeoff, when one of the spacecraft’s engines shut down due to excess vibration and the other engines had to burn longer to compensate. But the biggest problem occurred two days into the mission, when an oxygen tank exploded in the Service Module, causing power outages, loss of cabin heat and a shortage of potable water. Astronauts Jim Lovell, Jack Swigert and Fred Haise then squeezed into the Lunar Module, taking oxygen through a hose. After several days of work on the ground and in space, the Lunar Module reentered the atmosphere and splashed into the Pacific Ocean on April 17. A NASA investigation later found that the insulation in the exploded tank was damaged. Apollo 13, a movie about the mission, was released in 1995.
April 13, 1953: Project MKUltra, an illegal CIA mind control program, was sanctioned. The experiments on unwitting Americans (including prostitutes, mental patients and addicts) were used to identify and develop drugs for interrogation and torture, which would have been used on Soviet, Japanese, North Korean and Cuban subjects. Scientists administered LSD to the patients and used hypnosis to manipulate their thoughts, among other experiments. The project was halted in 1973, and many documents pertaining to it were destroyed during the Watergate cover-up. Following a congressional investigation, President Gerald Ford issued an executive order prohibiting experiments on human subjects without their consent. CIA officials later claimed the program was a symptom of American paranoia about nuclear war and Communist spies—they also apologized and gave compensation to the test subjects and their families.
April 15, 1912: The RMS Titanic sank on its maiden voyage from England to New York. The ship, operated by the White Star Line, was equipped with three engines, and its compartments were allegedly watertight and “unsinkable.” But that was proven wrong when the Titanic struck an iceberg in Canada and the compartments were breached, causing the ship to break in two. Amid all the carnage (1,500 dead, half empty lifeboats leaving the ship, etc) there was one saving grace: crew members used the (then state of the art) Marconi wireless equipment onboard the Titanic to summon help, and the radio contact between the ship and the shore, limited though it was, helped emergency crews get to the ship sooner.
April 17, 2013: An explosion at a fertilizer factory in West, Texas killed 15 people and injured 160. The trouble started with a fire in the factory’s seed room, which burned for 22 minutes despite firefighters’ best efforts. Ammonium nitrate fertilizer, a corrosive substance, was also stored in the room, and as the fire got hotter the compound became progressively more unstable. When a piece of debris hit the bins of fertilizer, 28 to 34 tons of ammonium nitrate exploded, destroying the factory building and 50-75 homes in its vicinity, and flinging debris for 2.5 miles. While the cause of the fire was never determined, an investigation found that the ammonium nitrate was improperly stored and that plant workers did not have proper respiratory protection.