Long Beach, California - Investigators from the US Coast Guard boarded a cargo vessel Saturday in Long Beach that could be tied to the rupture of a pipeline which spilled an estimated 25,000 gallons of oil off the Orange County coast, the agency said.

Braden Rostad, chief of investigations for Los Angeles-Long Beach, determined that the MSC DANIT, a large container ship, was involved in a January 25 anchor-dragging incident during heavy weather at the Ports of Los Angeles and Long Beach, the Coast Guard said in a statement.

The anchor-dragging occurred near a pipeline that runs from an oil platform to the Port of Long Beach. That pipeline was subsequently discovered to be the source of the Orange County oil spill on October 2, the statement said. An oil sheen was first spotted that evening by a vessel four and a half miles off Huntington Beach and then detected by the National Oceanic and Atmospheric Administration.

The pipeline was intact in October 2020 when the company that operates it last did an inspection, and the marine growth visible around the displaced section of the pipeline indicates the anchor drag likely was not recent, said US Coast Guard Captain Jason Neubauer.

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Investigators suspect an initial anchor strike displaced part of the pipeline many months before the spill, stripping away its concrete casing and causing it to be more vulnerable to other potential anchor strikes or environmental stressors.

As they attempt to determine when that first strike occurred, the investigating team is focusing on a storm that brought strong winds to the area over the course of two days in late January.

Data of vessel movements reviewed by the Los Angeles Times show MSC DANIT moving over the pipeline while in high winds January 25, before eventually moving out to the channel near Catalina Island.

The Coast Guard has designated Mediterranean Shipping Company, SA, the operator of the vessel, and Dordellas Finance Corp, its owner, as parties in interest in the ongoing investigation.

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Those designations provide the owner and operator of the MSC DANIT the opportunity to be represented by counsel, to examine and cross-examine witnesses, and to call witnesses who are relevant to the investigation.

The MSC DANIT is just one of several ships under investigation, said Lieutenant SondraKay Kneen, a spokesperson for the Coast Guard’s investigation team. However, Neubauer said no other ship owners or operators have received the "party in interest" designation.

Coast Guard investigators plan to bring in experts to determine how long ago the pipe was damaged and when it began leaking.

The Coast Guard also sent its own team of divers to gather evidence.

Multiple state and federal investigative agencies are already examining whether any criminal violations occurred with the pipeline leak, which spilled into the waters off Huntington Beach two weeks ago.

The FBI is now assisting with the criminal investigation, which among other things is examining whether there was a negligent discharge of oil into navigable waters.