After an unknown powder and a threatening letter arrived at a drafting equipment business in Centennial, a Hazmat crew followed soon after.
Late Monday afternoon, South Metro Fire evacuated the building on South Revere Parkway just south of Arapahoe Road.
The Hazmat team determined the powder was not toxic.
The Arapahoe Sheriff's Office still wants to know who sent it and why.
Copyright 2016 KUSA