Two bombs exploded in the crowd near the finish line of the Boston Marathon Monday afternoon, killing at least three and injuring more than 100, turning the world's oldest marathon into a scene of blood and terror.
Following is a list of some of the worst bombings in the United States in recent decades:
On Sept. 11, 2001, four commercial jets were hijacked by 19 al-Qaida militants and used as suicide bombs, bringing down the two towers of World Trade Center in New York City and crashing into the Pentagon. Nearly 3,000 people were killed in New York, Washington and Pennsylvania.
On July 27, 1996, a bomb exploded at Centennial Olympic Park in Atlanta during the Summer Games, killing two people and injuring more than 100. Eric Robert Rudolph was arrested in 2003. He pleaded guilty and was sentenced to life in prison.
On April 19, 1995, a car bomb outside the Murrah Federal Building in Oklahoma City killed 168 people and injured more than 500, the deadliest U.S. bombing in 75 years. Timothy McVeigh and Terry Nichols were convicted. McVeigh was executed in 2001 and Nichols was sentenced to life in prison.
On Feb. 26, 1993, a bomb in a van exploded in the underground World Trade Center garage in New York City, killing six people and injuring more than 1,000. Five extremists were eventually convicted.
On May 16, 1981, a bomb exploded in a men's bathroom at the Pan Am terminal at New York's Kennedy Airport, killing one man. A group calling itself the Puerto Rican Armed Resistance claimed responsibility. No arrests were made.
On Dec. 29, 1975, a bomb hidden in a locker exploded at the TWA terminal at New York's LaGuardia Airport, killing 11 people and injuring 75. Palestinian, Puerto Rican and Croatian groups were suspected, but no arrests were made.
On Jan. 24, 1975, a bomb went off at historic Fraunces Tavern in New York City, killing four people. It was one of 49 bombings attributed to the Puerto Rican nationalist group FALN between 1974 and 1977 in New York.
On Jan. 27, 1972, a bomb wrecked the New York City office of impresario Sol Hurok, who had been booking Soviet artists. One person was killed and nine others were injured, Hurok among them. A caller claiming to represent Soviet Jews claimed responsibility, but no arrests were made.