For some New Yorkers, yesterday's bombing may have brought back memories of a similar incident in 1994.
On December 22 of that year, a firebomb exploded onboard a crowded 4 train near Fulton Street.
More than 3 dozen passengers were injured.
Unemployed computer programmer Edward Leary was convicted of building and setting off the device, which was made of mayonnaise jars, gasoline and flashlight batteries.
Investigators said he carried out the attack in an attempt to extort millions of dollars from the transit authority.
Leary is now serving a 94-year prison sentence.