Ice-like crystals have formed on the 100-ton containment box made of steel and concrete, forcing crews to suspend action on the attempt to contain the oil leak in the Gulf of Mexico. The buildup made the box too buoyant and clogged it up, meaning workers had to lift it from its carefully positioned location over the leak site Saturday and move it to the side while they attempt to unplug it. “I wouldn’t say it’s failed yet,” said BP chief operating officer Doug Suttles. “What I would say is what we attempted to do last night didn’t work.”