A police captain and secretary were taken to the hospital after opening mail with an unknown substance inside the Green Bay Police Department Monday.
A hazmat crew was called to the department and is investigating.
Around 3:30 p.m. Monday afternoon, the two opened an overnight envelope on the second floor, according to Green Bay Police Chief Andrew Smith.
Both started feeling dizzy and nauseous, he said. The two were given Narcan as a precaution and sent to the hospital.
The building was evacuated and staff was sent home. The room where the envelope was opened was also sealed off, Chief Smith explained.
"Nobody knows what we're dealing with right now," said Lt. Cody Johnson with the Green Bay Metro Fire Department.
Both the captain and secretary are feeling better, Chief Smith said. They are no longer feeling the effects of what they felt earlier and were back at work Tuesday.
There is no update on what was inside the envelope, authorities said.
A piece of suspicious mail was found Tuesday at the Oak Creek Police Department, south of Milwaukee, according to a Postal Inspection Service spokesperson. No one was hurt in the incident and it is not believed to be related to the Green Bay case, the spokesperson said.
In Green Bay, the plan is to seal the envelope and send it to the FBI for investigation and analysis, Chief Smith said.
People should be let back into the building around 7 p.m.
NBC26 has a crew on the scene and will update this story as we learn more.
