Authorities stepped up security ahead of Fourth of July celebrations.

The NYPD deployed its entire air and sea fleets. Counterterrorism officers removed all trash cans from viewing areas of the Macy's fireworks show, as well as utilized bomb-sniffing dogs.

Crews in Boston welded shut manhole covers and restricted items like backpacks and coolers on wheels.

This year's Independence Day celebrations were among the first major events since the deadly marathon bombings in April. Officials say the bombers had originally considered staging their terror plot during today's festivities.