Milwaukee Fire Department crews responded to a hazmat scare at the Milwaukee County Safety Building.The incident began after the Milwaukee County District Attorneys Office reported that a staff member opened a piece of mail containing a white substance. The item was opened in an isolated area of the office.Watch: Crews respond to hazmat scare after white powder delivered to Milwaukee County DA's office Crews respond to hazmat scare after white powder delivered to Milwaukee County DA's officeEmergency personnel responded, and no one was medically affected by the incident, according to the DA's office. The source of the mail remains unclear.As of 3:30 p.m. Monday, Dec. 23, hazmat crews were still on the scene when TMJ4 arrived. TMJ4 has reached out to the fire department for more details and will provide updates as they become available .Its about time to watch on your time. Stream local news and weather 24/7 by searching for TMJ4 on your device.Available for download on Roku, Apple TV, Amazon Fire TV, and more.Report a typo or error // Submit a news tip