The cast and crew endured over six months of grueling six-day, 70-hour weeks on an isolated set. At one point, Mary Elizabeth Mastrantonio had a physical and emotional breakdown on the set and on another occasion, Ed Harris burst into spontaneous sobbing while driving home. Cameron himself admitted, "I knew this was going to be a hard shoot, but even I had no idea just how hard. I don't "ever" want to go through this again". For example, for the scene where portions of the rig are flooded with water, he realized that he initially did not know how to minimize the sequence's inherent danger. It took him more than four hours to set up the shot safely. Actor Leo Burmester said, "Shooting "The Abyss" has been the hardest thing I've ever done. Jim Cameron is the type of director who pushes you to the edge, but he doesn't make you do anything he wouldn't do himself." A lightning storm caused a 200-foot (65 m) tear in the black tarpaulin covering the main tank. Repairing it would have taken too much time, so the production began shooting at night. In addition, blooming algae often reduced visibility to 20 feet (6 m) within hours. Over-chlorination led to divers' skin burning and exposed hair being stripped off or turning white.