"Whenever anything went wrong it became usual to attribute it to Snowball."
George Orwell, Animal farm(Reuters) - Two bombs packed with ball bearings tore through crowds near the finish of the Boston Marathon, killing three people and triggering a massive hunt for those behind an attack the White House said would be treated as "an act of terror".
Officials said more than 100 people were wounded by the devices, which were packed with gunpowder and shrapnel to maximize injuries, according a senior law enforcement official briefed on the investigation who declined to be named.
