RIVERTON, Iowa (AP) — Fremont County authorities are blaming a cigarette for starting a fatal fire in southwest Iowa. The Daily Nonpareil reports that the death of 66-year-old William Daniel on Tuesday was ruled an accident, a result of carbon monoxide poisoning.

Fire crews from Riverton, Sidney and Hamburg were dispatched to the Riverton home about 6:20 a.m. State fire investigator John Ticer says the fire was contained to the master bedroom. The Sheriff’s Office says the fire was started by an improperly discarded cigarette on Daniel’s bed.