“Bombs that shook the city’s subway system last week exploded within 50 seconds of each other [The New York Times’ grammar checkers don’t know that this should be “one another”?? — FmH] and were made of high explosives, not homemade material, police said Saturday.

The three bombs went off nearly simultaneously at about 8:50 a.m. Thursday, said Deputy Assistant Commissioner Brian Paddick said, revising earlier accounts that they occurred within a 26-minute span. An explosion tore through a double-decker bus nearly an hour later.

New information about the timing of the explosions also suggested they were detonated with synchronized timers rather than by suicide bombers, although officials said nothing had been ruled out.” (New York Times )