Hazmat officials responded to St. Joseph’s City Hall on Monday after a white substance was found in a letter mailed to the mayor.

A white substance mailed to St. Joseph City Hall that forced partial evacuation of the building was later determined to be human ashes.

Emergency officials responded at around 11 a.m. on Monday after an unknown substance was found in an envelope addressed to the mayor, according Mary Robertson, the city’s communications and public relations manager. The envelope had been sent to the city’s finance department, where the department’s purchasing agent noticed the envelope had been slit open and taped shut.

“There was a baggie with some kind of a substance in there, (we) immediately called the (police department) to have them come and take care of it,” Robertson said.

The St. Joseph Police Department, the fire department, the Region H Hazmat Team as well as the FBI responded and evacuated the finance department until the substance, which Robertson described as white and granular, could be identified.

“Staff is trained to look for unusual and suspicious packages,” Robertson said. “In this particular case, the envelope had been opened and resealed, so it’s obvious that there was something in there and we do treat it as hazardous until we know otherwise.”

Bill Brinton, director of the Region H Hazmat Team and Buchanan County emergency management coordinator, said his team was able to identify the white substance in what he called a “very unusual” case.

“It was actually ashes from a former city employee whose family sent it here to be spread over a garden at City Hall,” Brinton said.

The envelope contained a letter explaining the cremains. Additionally, a test performed by the Hazmat team confirmed the substance to be human ashes.

According to St. Joseph Mayor Bill McMurray, the letter was sent from Oklahoma City, but he did not recognize the sender’s name.

“Of course my first thought was, ‘It’s anthrax, I guess we’re all done now,’” McMurray said of the moment he looked at the envelope and felt a small bag in it. “Thank God it wasn’t that.”

The ashes and letter have been turned over to the St. Joseph Police Department for further investigation.

Jessica Kopp can be reached

at jessica.kopp@newspressnow.com.

Follow her on Twitter: @NPNOWKopp