Police believe an Omaha man found dead in his car in West Des Moines died of carbon monoxide poisoning. Thirty-nine-year-old James Twadell had traveled to West Des Moines on Friday to trim trees for a friend.

He planned to continue the work on Saturday. Twadell couldn’t find an open campground and refused to stay at the home of his friend, so he decided to sleep in his Chevy Blazer in an adjacent church parking lot. Twadell was found dead in his vehicle the next evening after failing to show up to trim trees.

Police believe he was using a charcoal grill to stay warm and likely died after inhaling carbon monoxide.