A letter containing what investigators are calling a "biohazard" has been sent to a Pennsylvania police barracks and has sickened three employees.
State police and federal authorities say two state troopers and a civilian staff member became ill Thursday afternoon immediately after one of the troopers opened the letter at the Carlisle barracks and were taken to a hospital.
The barracks was evacuated for several hours. The three employees were discharged from the hospital Thursday night and returned to work Friday. The FBI is examining the letter and the envelope containing it.
Trooper Brent Miller says the investigation has "ruled out all serious biohazards" but he can't provide further information on what the letter contained. He says the letter was addressed to the trooper who opened it.