Here is a list of some of the worst bombings in the U.S. dating to the 1800s, including some famous attempts that failed:
-- April 15, 2013: Two bombs explode in the packed streets near the finish line of the Boston Marathon, killing three people and injuring at least 130.
-- Jan. 17, 2011: A backpack bomb is placed along a Martin Luther King Day parade route in Spokane, Wash., meant to kill and injure participants in a civil rights march, but is found and disabled before it can explode. White supremacist Kevin Harpham is convicted and sentenced to 32 years in federal prison.
-- May 1, 2010: Pakistani immigrant Faisal Shahzad leaves an explosives-laden SUV in New York's Times Square, hoping to detonate it on a busy night. Street vendors spot smoke coming from the vehicle and the bomb is disabled. Shahzad is arrested as he tries to leave the country and is sentenced to life in prison.
-- Dec. 25, 2009: The so-called "underwear bomber," Nigerian Umar Farouk Abdulmutallab, is subdued by passengers and crew after trying to blow up an airliner heading from Paris to Detroit using explosives hidden in his undergarments. He's sentenced to life in prison.
-- Sept. 11, 2001: Four commercial jets are hijacked by 19 al-Qaida militants and used as suicide bombs, bringing down the two towers of New York City's World Trade Center and crashing into the Pentagon. Nearly 3,000 people are killed in New York, Washington and Pennsylvania.
