Homicide and arson detectives on Sunday were investigating a carbon monoxide leak inside a restaurant at a shopping mall on New York's Long Island that left one person dead and 27 other people injured.
The Legal Sea Foods restaurant at the Walt Whitman Mall in Huntington Station, about 40 miles east of New York City, remained closed on Sunday after the leak detected on Saturday night forced the evacuation of the establishment and three nearby eateries.
Suffolk County police responded to the mall around 6 p.m. after reports that a Legal Sea Foods employee had collapsed and fallen down a flight of stairs.
As police cleared the restaurant of its customers, officers found 55-year-old manager, Steven Nelson, unconscious in the basement. He died of cardiac arrest as he was being transferred by ambulance to Huntington Hospital, according to hospital spokeswoman Julie Robinson-Tingue.
Twenty-seven other victims, including four ambulance personnel and three police officers, were transported to five area hospitals with non-life threatening symptoms, police said. Most of the victims were restaurant workers.
Both homicide and arson squads from the Suffolk County Police Department were investigating the poisonings, with the restaurant's heating equipment believed to be the source of the carbon monoxide leak, police said.
A Suffolk County police spokeswoman declined to comment when asked whether foul play has been ruled out.
The incident appeared to be confined to the basement of the restaurant, Suffolk County Police Lieutenant Jack Fitzpatrick said on Saturday.
The restaurant is free standing but adjoins the popular mall, which remained opened during the incident was expected to stay open as normal on Sunday.
Two restaurants near Legal Sea Foods, Panera Bread and The Cheesecake Factory, also were evacuated on Saturday evening, The Cheesecake Factory had reopened on Sunday but Panera Bread remained closed.
Legal Sea Foods, which has locations around the northeastern and mid-Atlantic United States, said in several postings on Twitter it was "devastated by the news of carbon monoxide poisoning," and that it was "profoundly saddened to learn of the tragic death of our General Manager Steve Nelson," adding "Our thoughts and prayers are with his family."
A restaurant representative who answered the phone at company headquarters in Boston on Sunday said company officials were unavailable to comment until Monday.
Carbon monoxide, or CO, is an odorless, colorless gas that can cause sudden illness or death, according to the Centers for Disease Control and Prevention. CO is found in combustion fumes, such as those produced by car engines, gas ranges or heating systems.
Symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion, the CDC said on its website.