This Day in History

Nuclear Submarine USS Scorpion Sinks, Cause Unknown (1968)
On May 21, 1968, the crew of the US Navy's Scorpion submarine engaged in communications with land stations. Six days later, the submarine was reported overdue. After an unsuccessful search, the Scorpion and its crew were "presumed lost." However, in October, a Navy research ship located sections of the submarine's hull in approximately 10,000 feet (3,048 m) of water about 400 miles (644 km) southwest of the Azores. What are some theories about how the Scorpion may have sunk? Discuss

Rajiv Gandhi Is Assassinated (1991)
When his brother Sanjay Gandhi died in a plane crash in 1981, Rajiv Gandhi—then an airline pilot—was drafted into politics by his mother, Indian Prime Minister Indira Gandhi. When she was assassinated in 1984, he succeeded her as prime minister. In 1987, he sent peacekeeping forces to Sri Lanka in an unsuccessful attempt to end Tamil-Sinhalese violence. Following allegations of corruption, he resigned as prime minister in 1989. He was assassinated in 1991. How and by whom was he killed?

Levi Strauss Patents Iconic Metal Rivet for Reinforcing Pants Pockets (1873)
If you are wearing blue jeans, chances are a version of tailor Jacob Davis's invention is hugging your hips right now. Davis did not invent jeans—that was the more famous Levi Strauss—but he did invent one crucial component: the copper rivets that reinforce the corners of the pockets, now ubiquitous on denim pants. Because Davis did not have the money to file the necessary patent paperwork, he wrote to Strauss—then Davis's fabric supplier—suggesting they apply together. How did Strauss respond?