'White substance' in envelope that triggered hazmat response to Milwaukee County DA's office determined to be sugar

MILWAUKEE (CBS 58) -- A hazardous materials team responded to the Milwaukee County Safety Building Monday afternoon, after a staffer opened an envelope with an unidentified white powder inside.

For several hours, Milwaukee hazmat crews swarmed the district attorney's office downtown.

All staffers are safe after that powder was determined to be sugar.

We've also confirmed the letter was sent from the Milwaukee County Jail just across the street.

For a time, the situation was uncertain enough to trigger an office shutdown in one of the city's key criminal justice buildings.

Earlier in the evening, The DA's office released the following statement:

"A staff member of the office opened a piece of mail containing a white substance. The item was opened in an isolated area of the office. Emergency personnel have responded to the office and no one is suffering any medical impact from the incident."

A staffer opened an envelope at about a quarter to three in an isolated area of the district attorney's fourth-floor office.

A white powder was inside. The staffer did not recognize the substance and alerted authorities.

The Milwaukee Fire Department responded, then called for the hazmat team.

When that team arrived on scene, they assessed the situation and geared up in airtight suits.

MFD Battalion Chief Jeremy Starr said, "It's just going to keep them protected to the higher for what they expect it could be. To maintain safety, not only for ourselves, but also for members inside."

Hazmat said they spent about an hour inside the office.

Starr said, "They tested the substance for any chemical, biological, nuclear, any of those sorts. Everything came up negative at this time."

No evacuations were necessary, and no one was hurt. And the building remained open as people continued normal court and clerk operations.

Crews take any report of a suspicious substance seriously.

Back in 2001, five Americans were killed and 17 more were sickened when anthrax was mailed to government buildings. It was the worst biological attack in US history.

It's a big reason why local hazmat teams work in coordination with the state and FBI on investigations.

After the building was cleared, the package was transferred over to FBI, which will take over the investigation.

The scene was cleared at 5:15.

We do not yet know the identity of the sender.