On April 15, 2013, two bombs housed in kitchen pressure cookers detonated near the finish line of the Boston Marathon. At least three people were killed and more than 200 injured by the blasts. Just days later, the entire city of Boston and its surrounding areas came to a screeching halt as one of the U.S.'s largest manhunts got underway.
The FBI released photos of two suspects believed to be responsible for the Boston Marathon bombings. The suspects shot and killed an MIT campus police officer, carjacked an SUV and tossed homemade explosives at law enforcement officials who pursued them.
While one suspect, Tamerlan Tsarnaev, was shot and killed by police, the other – his brother Dzhokhar Tsarnaev -- slipped into the darkness of a residential neighborhood. The ensuing manhunt included dozens of law enforcement officers from national, state and local agencies, as well as helicopters hovering overhead. Residents of Boston and surrounding suburbs were ordered to "shelter in place." Officials stopped public transportation systems, instituted a "no fly zone" over the city, closed universities and schools, and shuttered area businesses -- an unprecedented shutdown of a major U.S. city.
The manhunt continued until Tsarnaev was captured and taken into custody on April 19. Although estimates are still coming in, the manhunt is expected to have cost more than $1 billion, which may make it the most expensive one to date in U. S. history [sources: Brooks, CBS News, Minch].