Los Angeles A mysterious oil spill that killed hundreds of birds on the Southern California coast was probably not caused by natural seepage from the ocean floor, investigators said.

Officials said Friday they came to that conclusion after testing oil wiped from birds that turned up on a 90-mile stretch of coast more than a week ago.

“We’re assuming it’s not a seepage, because what we’re seeing on the birds is oil that’s weathered, not the slimy, wet stuff that comes from the ground,” said Ken Mayer of the state Department of Fish and Game’s Office of Spill Prevention and Response.

Investigators said oil wells and pipelines near the Ventura River were a possible source, theorizing they could have become uncapped or broken during the area’s recent storms.

Professors quit over gun in performance

Los Angeles Two tenured art professors have resigned from the University of California, Los Angeles, because the school refused to suspend a graduate student who may have used a gun during a classroom performance art piece.

Chris Burden and Nancy Rubins, internationally known artists who taught at UCLA for more than two decades, filed their retirement papers Dec. 20.

In the brief performance on Nov. 29, the student appeared to point a loaded handgun at his head and pull the trigger, a student and law enforcement officials told the Los Angeles Times.

The weapon didn’t fire, but after the student left the room a noise that sounded like a gunshot was heard outside.

Police said no one was hurt and it wasn’t known if the firearm was real. Prosecutors said there wasn’t enough evidence for charges, said Jane Robison, a spokeswoman for the Los Angeles County District Attorney’s Office.

The student was allowed to continue his studies after the dean’s office decided that suspension wasn’t warranted.

Rape accusers deemed incompetent

Leesville, La. A man won’t face trial on charges he raped three residents of a short-term home for the mentally disabled because his accusers were found incompetent to testify against him.

Prosecutors dropped six aggravated rape charges Friday against Louis Glenn Dowden, who was a resident training specialist at the Leesville Developmental Center.

Prosecutors said the case rested largely on the victims’ testimony and the judge ruled them incompetent to testify following a two-day hearing. The victims all have IQs under 70.

Dowden was arrested in March 2002 after state officials began investigating the rape allegations. He was also put on administrative leave by the state.

Dowden’s attorney did not immediately return a call seeking comment Saturday.

Bob Johannessen, spokesman for the state Department of Health and Hospitals, said the case demonstrates how difficult it is to secure a rape conviction if the victim has a developmental disability.

“Ultimately, the burden is going to fall on our agency and on others who provide services to individuals with disabilities to put in the proper safeguards,” he said.

250 cruise ship passengers fall ill

Port Canaveral, Fla. More than 250 passengers aboard a cruise ship fell ill with a stomach virus while touring the western Caribbean, cruise line officials said Saturday.

About 233 of the 3,465 passengers aboard the Mariner of the Seas became sick after the vessel left Port Canaveral on Jan. 16 for a seven-day cruise through the western Caribbean. The ship was expected to return early today. Twenty of the vessel’s 1,190 crew members also showed symptoms.

Michael Sheehan, a spokesman for Royal Caribbean International, described the illness as “your typical 24-hour stomach virus and nothing more” and blamed a sick passenger for bringing it on board.