White powder accompanied by threatening notes prompted evacuations at three downtown Denver buildings housing state agencies Monday, while a powdery substance at a suburban building forced the evacuation of a state police call center.
Authorities say the substances in all four cases turned out to be harmless but it's not clear yet whether they're all related.
An envelope sent to the state Department of Natural Resources near the State Capitol contained sugar and one sent to the World Trade Center contained a sugar substitute. Another envelope sent to the building housing the Department of Regulatory Agencies also contained a sugar substitute.
In Lakewood, an employee opening a letter sent to the state Department of Agriculture came into contact with a powder. That forced the evacuation of the four-story building that houses several state agencies, including the state patrol's Denver dispatch center.