HUNTINGTON BEACH, Calif. (AP) — Coast Guard investigators say an underwater Southern California oil pipeline was likely struck by an anchor several months to a year before a major leak spilled tens of thousands of gallons of crude.

The U.S. Coast Guard says Friday that a large ship may have snagged the massive pipeline off Huntington Beach, but that might not have actually fractured the pipe.

Capt. Jason Neubauer says other ships' anchors may have struck the pipe later, which was dragged along the seafloor and spewed oil last weekend from a slender crack.