Dillinger was interviewed by investigators a few days after the fire, said Mayor Forrest Schnobrich. She never returned to work after the interview and later resigned, he said. She could not be reached for comment last week, either at her home or by telephone.

Humphrey said Dillinger repeatedly told investigators she did not start the blaze.

“She was very cooperative, but she denied up and down she had anything to do with the fire,” he said.

Local officials knew the state auditors were scheduled to arrive that day. The audit of city finances was being done as the result of a petition signed by more than 160 local residents.

Larger communities in Iowa are audited annually. Casey, a city of about 425 about 85 miles east of Omaha, hadn’t been audited in more than 20 years.

Residents in Casey and three other small communities petitioned for an audit in the 2014 fiscal year.

Judi Zimmerline, who owns a hair salon in Casey, was an organizer of the petition drive. It was circulated, she said, because an audit hadn’t been done for so long and because there were suspicions of shoddy bookkeeping.