Two Hydrogen explosions rip Navy Yard shops at Boston, Massachusetts. View of fallen debris and twisted heavy steel girders. Officials inspect the area. Two signs. One reads 'Hydrogen Dangerous Keep open flame away' and the other reads 'Oxygen Dangerous Keep open flame away'.
Wrecked Navy yard due to two hydrogen blasts in Boston,Massachusetts. View of the destroyed acetylene plant in the Charlestown Navy Yard. Two Navy officers inspect the blast site as shells lie on the ground.
Dogs trained for a stage in Boston, Massachusetts. The dogs as they raise their front limbs and sit on their haunches. A trainer instructs the dogs. A dog does repeated back flips. A dog jumps for a jump rope and then for a tandem jump rope. A dog sits on a rope: The dog balances four paws on a single suspended rope and then raises his front two paws in the air while still balancing on the rear legs.