A 64-year-old woman died when her trailer caught fire on Tuesday in southwest suburban Oak Lawn.

Diana Lynch was inside the trailer when it caught fire in the 9000 block of South Cicero, according to Oak Lawn police and the Cook County medical examiner’s office.

Police said they believe the fire started when Lynch fell asleep while smoking.

Lynch was taken to Christ Medical Center in Oak Lawn, where she was pronounced dead at 10:14 a.m., according to the medical examiner’s office. An autopsy Wednesday found she died of carbon monoxide toxicity and thermal injuries from the fire.

The Oak Lawn Fire Department could not provide details about the fire on Wednesday.