LINCOLN, Neb. (AP) — Authorities have identified the elderly man and woman who died in a weekend house fire.

Lincoln Police said 74-year-old Ervin Martin and 69-year-old Janice Ortiz died Saturday night in the fire.

Initially, firefighters thought they were responding to a medical problem, but they encountered smoke and flames when they opened the door of the home near where Interstates 80 and 180 meet.

Fire investigators determined that a lit cigarette started the fire.

Autopsies will be performed to confirm they died from fire-related injuries. Authorities believe Martin and Ortiz died from smoke inhalation and burns.