Anthrax scare at Brooklyn foster care program

A letter containing a mysterious white powder arrived at a Brooklyn, New York-based foster care program on December 9, representing one of three potential terrorist threats in the area in a week's time.   
The incident took place in Brooklyn's Dyker Heights neighborhood at Mercy First, which runs the Angel Guardian Home, a non-profit social services agency that operates foster homes. The letter was addressed to the Angel Guardian Home, the Brooklyn Eagle reports. Three workers came into contact with the powder. The workers were treated at the scene and an analysis of the powder revealed it to be harmless.
A female employee opened the letter at 12:10 pm on December 9 and powder spilled on her and two male employees. Police were called to the scene while the three workers were decontaminated by the Police Department's Hazardous Materials team. The Mercy First campus was evacuated and the security measures remained in place for approximately five hours.
Police are still investigating to determine who sent the letter to set off the emergency, according to the Brooklyn Eagle.  
The incident took place a day after a bomb scare outside the New Corner Restaurant in Brooklyn's Bay Ridge neighborhood. On December 8, a mysterious package was left outside the restaurant and was later determined not to be an explosive. On December 4, a 40-year-old man walked into Brooklyn's 68th Precinct station house carrying a bag he said was an explosive he found at an apartment building. The man also said there were explosives in a van parked outside the apartment house. The man was arrested and charged with making a terrorist threat along with placing a false bomb.