Update(7:00 AM 6/19):  Omaha fire officials say a man found dead inside a burning house apparently started the fire by setting a mattress on fire.

Officials found the body of 55-year-old Dennis Hansen inside the burning home in southeast Omaha Sunday morning. An autopsy showed he died of smoke inhalation.

Capt. Tim McCaw says Monday that investigators determined a mattress in a bedroom was intentionally ignited. He says there’s no evidence to suggest that anyone outside the home set the fire and all accidental causes have been ruled out.