HUNTINGTON BEACH, Calif. (AP) — An Associated Press review of more than 10,000 reports submitted to federal regulators shows at least 17 accidents on pipelines carrying crude oil or other hazardous liquids have been linked to anchor strikes or suspected anchor strikes since 1986.

The reports illuminate a history of problems as investigators search for the cause of an oil pipeline crack off the Southern California coast that fouled beaches.

Records show in some cases anchor strikes were never conclusively proven, such as 2012 leak from a pipeline in Louisiana. Others were clear. In 1992, an anchor was dragged over a pipeline in the Gulf of Mexico that later broke open.