California oil pipeline leak: Mystery continues to swirl around cause

Investigators searching for the cause of an oil pipeline break off the Southern California coast have pointed to the possibility that a ship anchor dragged the line across the seabed and cracked it, but two videos released so far provide only tantalizing clues about what might have happened 100 feet (30 meters) below the ocean surface.

The slight bow in the line displayed in one video "doesn’t necessarily look like anchor damage," Frank G. Adams, president of Houston-based Interface Consulting International, said in an email. When a pipeline is hit by an anchor or other heavy object "that typically results in physical damage that may lead to a fracture."

Ramanan Krishnamoorti, a petroleum engineering professor at the University of Houston, said he considered the video that runs along a bend in the line "revealing."