Fire and police investigators are continuing to interview witnesses and gather evidence in a Sunday night fire that ripped through part of the old General Mills facility, according to city officials.

“We are retrieving and logging evidence, which is a time-consuming process in a space that size and with that much debris,” said Sgt. Don Shepard, Johnson City Police Department Criminal Investigation Division supervisor. “Fire marshals and police investigators are also interviewing witnesses and others who were nearby at the time of the fire.”

Shepard confirmed there was still a person of interest in the case, but charges have not yet been filed.

“We believe that our investigation will provide some answers sooner rather than later,” he said.

The fire was confined to a section of the building directly behind the mill office. The roof of that section collapsed onto the third floor, which has limited investigators’ access to search for the origin and cause of the fire.

Firefighters were dispatched to the fire at 9:24 p.m., about 10 minutes after a JCPD officer responded to a burglary in progress reported at the mill, which is located at 500 W. Walnut St. That call came from the prospective property owner, Grant Summers, who had placed trail cameras inside the building in hopes of catching the person or people responsible for repeatedly vandalizing the building with graffiti.

When the officer arrived, he encountered a man inside the building. As the two talked, the officer noticed a fire. The man at the scene has not been identified at this time. Police Chief Mark Sirois said Monday the person was detained for questioning and taken to police headquarters, but then had a medical problem and was transported to an area hospital, delaying his questioning.

Anyone with information about the fire can contact the fire marshal’s office or police department. The Criminal Investigation Division’s number is 434-6166. To remain anonymous, call Crime Stoppers at 434-6158. To send a confidential tip, text 423JCPD and your tip to 847411 (TIP411) or send a tip to Messages can also be sent via the JCPD website,