There were four of them yesterday in the metro area.
DENVER -- Three downtown Denver buildings and a fourth government building in Lakewood were briefly evacuated Monday after a mysterious powder in a letter was sent to each one of the buildings.
All four letters had a threatening note that contained the same wording and apparently targeted state offices, authorities said. All four buildings house state offices but it's not known if all the cases are connected.
"We don't want to give credance or credibility to people who are nothing more than crackpots, but on the flipside, we have to err on the side of safety and treat these as credible until we can determine otherwise," said Denver Fire Department spokesman Phil Champagne.
Hazardous materials crews were called to the first two Denver buildings, which are blocks apart, at about 1 p.m.
The letter that was opened first was sent to the Centennial government office building, located at 13th Avenue and Sherman Street. About 200 to 300 people were evacuated after four people were exposed to the powder. The second package arrived at the World Trade Center building, located at 16th Avenue and Broadway Street.
Firefighters received calls about both locations within 20 minutes of each other and quickly determined that the substance was sugar and a sugar substitute.
A third evacuation was called at about 4 p.m. at the office for the Colorado Department of Agriculture, located at 700 Kipling Street in Lakewood. Authorities also determined that the white powder in the third letter was not harmful.
At about 5 p.m., the office of the State Regulatory Agency, also opened an envelope that contained white powder. That building is located 15th Avenue and Broadway Street.
A Denver Fire Department spokesman said that they are more concerned about the threatening letters than the powder.
Denver police and federal postal inspectors are investigating the hoaxes. The hoaxes are concerning, but the false alarms do allow for training too, firefighters said.
"For us, we become quicker. We set up our decon team, it's good practice, but there becomes that point of demarcation, where it doesn't become productive anymore," Champagne said.