the investigation this morning by homicide and arson detectives focuses on heating equipment. the source of deadly carbon monoxide poisoning. >> it is scary that we were just sitting there. >> reporter: they were at the cheesecake factory at the walt whitman mall in huntington, new york, when the wait staff told the entire restaurant to get out. >> somebody came over, i think it was one of the waitresses. she said that you had to leave. >> reporter: police and emergency responders were called to the mall after a report that a woman had fallen and hit her head in the basement of legal sea foods. when authorities arrived and began investigating, they themselves reported feeling nauseated and dizzy, symptoms of carbon monoxide exposure. restaurants in the area immediately evacuated. >> we had to leave because i didn't want to blow up or anything like that. i didn't know how dangerous it was and they just told us to stay outside.