PALM SPRINGS, Calif.—A guest at a Palm Springs hotel room died last fall from carbon monoxide poisoning caused by a faulty pool heater, authorities said.

The Riverside County coroner's office announced the cause of death for Mark Ruf on Wednesday, according to the Los Angeles Times ( http://lat.ms/PR0XtW).

Ruf, a 48-year-old attorney from Cleveland, Ohio, was found dead on the floor of his room at the Curve Palm Springs Hotel & Resort on Nov. 13. Relatives notified police after Ruf failed to return from his California vacation.

Investigators concluded that carbon monoxide was leaking into the room from pool heating equipment below it that has since been removed, police Lt. Mitch Spike said.

Ruf died of "acute carbon monoxide poisoning," coroner's Sgt. Anthony Townsend said.

Ruf's family filed a lawsuit Tuesday that claims the hotel failed to properly investigate after another guest was sickened in the same room two weeks earlier.

The suit says the woman told hotel staff that she vomited and had tightness in her chest and other symptoms that improved when she opened a door and breathed fresh air.

The hotel's general manager declined on Wednesday to give his name and said he couldn't comment.