SUN PRAIRIE, Wis. (AP) — There will be no criminal charges against anyone related to an explosion in a southern Wisconsin city that killed a firefighter and leveled several buildings, the police chief announced Thursday.

The July 10 blast in downtown Sun Prairie happened after a subcontractor installing fiber communication lines struck a gas main and the gas ignited about 40 minutes later.

At a news conference, the city’s police chief, Patrick Anhalt, said companies working on the project exchanged and relied upon “incomplete and inaccurate information” and that law enforcement officials, including the county district attorney and state attorney general’s office, agreed that criminal charges weren’t warranted.

The chief blamed the accident on “miscommunication” but didn’t explain what exactly happened. Anhalt didn’t take questions but did make public a redacted copy of the investigation report. He said investigators conducted 67 interviews and examined 45 pieces of evidence and 400 pages of documents during their five-month probe.

The explosion killed Sun Prairie firefighter Cory Barr and injured eleven other people, including five other firefighters and a police officer. It also destroyed a home and six businesses, including a bar that Barr and his wife owned called the Barr House.

Firefighters and police evacuated dozens of people before the gas ignited.

Barr wasn’t on duty when the blast occurred, but family members said he felt compelled to help evacuate and secure his business. He and another firefighter had just left the Barr House when the explosion destroyed the building.

Sun Prairie, a city of about 30,000, is just to the east of Madison, Wisconsin’s capital city.

Court documents showed a utility-location worker failed to properly mark a natural gas line prior to the explosion. The search warrant request showed that investigators were looking for evidence to support a second-degree reckless homicide charge in the case.

Anhalt said Verizon Wireless contracted with Bear Communications for the fiber optic installation project. Bear Communications first subcontracted with Jet Underground, but then changed subcontractors to VC Tech, Anhalt said.

VC Tech proceeded with the project and, while engaged in “underground directional boring,” cut through a WE Energies gas line that was not completely marked, the chief said.

About 40 minutes later, the escaping gas ignited. The cause of the ignition was not determined, Anhalt said.

“This error appears to be the result of miscommunication between USIC, Bear Communications, Jet Underground, and VC Tech,” Anhalt said. “Prior to the explosion, conversations occurred between representatives of each of these companies, both on and off site, during which incomplete and inaccurate information was exchanged and relied upon.”