Roadside bombs tore through spectators near the finish of the Boston marathon Monday, bloodily ending more than a decade as Americans uneasily waited for the inevitable, knowing that sooner or later, no matter how many plots were foiled and attacks thwarted, the terrorists would eventually succeed.
As the nation reeled and security was ratcheted up, sometimes with immediate and visible effect (and more often unseen), Americans waited to learn whether the Boston attacks were a long-feared al-Qaeda strike or something else.
In Afghanistan, roadside blasts – sometimes crude, sometimes sophisticated – are the new normal; bombs are intended to kill and main, to rip though gatherings of worshippers or celebrants or spectators. That merciless tactic, which spread to Iraq and Syria and Mali and elsewhere, reached the United States on Monday.
The Boston blasts bore none of the "spectacular" hallmarks usually associated with al-Qaeda, but the group once led by Osama bin Laden was immediately suspected. Runners and spectators weren't high-profile targets: not embassies nor an attack on a U.S. warships nor turning fuel-laden airliners into human-guided missiles to destroy New York's twin towers or set the Pentagon ablaze. Yet no matter how small in the grim pantheon of terrorist strikes, the killing and maiming of innocent civilians at one of America's annual iconic events represented a strike at the heart of the United States.
Video of the first explosion, which tore through spectators on a Boston sidewalk, showed a plume of fire and smoke erupting vertically, suggesting that the explosive may have been in a container or trash can.
While sewer covers are routinely welded shut before major spectator gatherings like parades or public marathons, the precise locations of the bombs wasn't yet clear. There was no evidence – a severed head for instance – to suggest suicide bombers.