WHEAT RIDGE – A U.S. Postal Service distribution facility in Denver that handles 10 million pieces of mail a day for Colorado and Wyoming remained open Friday despite being ordered to shut down by city health officials because of a coronavirus outbreak investigation.

The agency said it is complying with federal safety guidelines and working with city officials to address their concerns.

The Denver Department of Public Health & Environment said it ordered the Postal Service to shut down the facility after the Postal Service refused to provide it with necessary information and inspectors were refused entry beyond the post office service counter on Wednesday.

“This was a measure of last resort, and the only remaining tool we have to get the facility management’s attention and secure public health compliance during a pandemic,” the department said in a statement.

The inspectors were turned away by a “random employee” because they turned up at the secure federal facility unannounced and did not try to arrange for access despite already being in talks with the Postal Service about the situation, USPS spokesman David Rupert said.

The 840,000-square-foot mail facility, the fourth largest in the United States, has about 2,000 workers who process incoming and outgoing mail for 6.3 million people in Colorado and Wyoming using about 900 trucks. The last time a worker there was confirmed to have COVID-19 was May 2, and there is no current outbreak there, Rupert said.

Danica Lee, the director of the health department’s inspections division, told KUSA-TV that there have been five cases at the facility.

Rupert confirmed that figure but said the Postal Service relies on public health officials to tell it when an employee has tested positive. He said it has participated in contact tracing investigations when it has been notified about cases.

In its order, Denver officials said the facility should remain closed until the facility can be sanitized and safety procedures, including employee being checked for symptoms and being required to wear face coverings, are followed. They also want the Postal Service to report any new coronavirus cases within 24 hours.

The Postal Service adheres to U.S. Centers for Disease Control guidelines and provides masks to all employees, but only those people whose work cannot avoid being within 6 feet (2 meters) of others are required to wear them, Rupert said. Employee screenings are not required by the CDC, he said.

While local health departments have shut down essential businesses like supermarkets because of outbreaks, the Postal Service says its mission is protected by federal law during times of emergency. Shutting down the mail hub would disrupt the delivery of such things as stimulus checks, medicine, mail ballots for the June 30 primary election as well as letters, Rupert said.

“We realize more than ever how important connection is. No one does connection better than the U.S. Postal Service,” he said.