A white powder that prompted the evacuation of two buildings at Camp Lincoln Tuesday afternoon turns out to be harmless, but federal officials have started a criminal investigation to determine who sent it to the base in envelopes that also contained threatening letters.
At least three letters were sent to Camp Lincoln, apparently from the same individual. When the first one was opened, the powder spilled out, leading to a lockdown of the base that kept more than 200 workers from leaving for several hours.
Crews from the Springfield Fire Department and the National Guard responded to the situation.
