On June1, 1863, Montgomery, Tubmanandseveral hundredblacksoldiers traveled up the riverin gunboats, avoiding remotely-detonatedmines that had been placed along the waterway.
They allegedly conspired to acquire plastic explosives (C-4) and build two bombs, affixing them to the bridge's support columns to be remotelydetonated on Monday.
Most roadside bombs are remotelydetonated using common household devices: cell phones, garage door openers, burglar alarms, key fobs, doorbells, or remote controls for toy cars.