Air India Flight 182

Air India Flight 182, a Boeing 747-237B, crashed off the southwest coast of Ireland on June 23, 1985, when a bomb exploded in the cargo hold. All 307 passengers and 22 crew members died. One passenger had checked in as "M. Singh". Singh did not board the flight. His suitcase containing the bomb was loaded onto the plane, however. "Mr. Singh" was never identified or captured. It was later determined Sikh extremists were behind the bombing as a retaliation for the Indian government's attack on the Golden Temple in the city of Amritsar, which is very important for the Sikhs. This was, at the time, the deadliest terrorist attack involving an airplane.