The bombs themselves had 1 hour timers on them, not trip wires. They were placed on the night of January 5th and found on January 6th, suggesting that they were never activated. Even if they were activated, there's no chance anyone would have been walking by at the exact moment they detonated, and it's not like a 1lb pipe bomb could damage the building.

It was either a distraction or some absolute retard, not something meant to actually harm anyone/anything.