The worst terrorist act in history were the attacks on the World Trade Center and the Pentagon on September 11, 2001. There had been a previous attack on the World Trade Center in 1993 when a car bomb exploded. Other major terrorist incidents include train bombings in 2004, the Lockerbie plane bombing in 1988, the suicide attack on the USS Cole in Yemen in 2000, and the Bali bombings in 2002.