CASPER, Wyo. (AP) — The city of Casper is investigating whether evidence is missing involving a wildfire that destroyed 14 homes.

The probe is beginning almost six months after city officials learned of an email sent by the fire chief asking an investigator to delete the "bad parts" of video of the blaze.

Fire Chief Kenneth King, who is planning to retire, said the email was a joke.

City Manager V.H. McDonald said Wednesday he did nothing to verify evidence wasn't missing beyond talking to King. McDonald did not talk to the recipient of the email, a fire inspector responsible for collecting evidence.

The fire spread from the city landfill Oct. 11, 2015, a day after a grinder ignited wood chips stored at the facility. The blaze spread during high winds and burned more than 15 square miles.