An almost unthinkable tragedy in East Greenbush where a woman who drew the attention of social services officials in Pennsylvania has killed her two daughters - ages 6 and 9 - and herself.  

It happened Tuesday morning on Rockrose Drive.  Police chief Christopher Lavin says it appears the mother, 47 year old Angela Mtambu, released several containers of compressed nitrogen gas in the bedroom.

Lavin says police got a call shortly after 1am from relatives concerned about their safety.  A brother says the woman was distraught over the suicide of her 23 year old son who had killed himself at the Rockrose Drive residence in April. 

An Amber Alert had been issued in Pennsylvania after authorities there received information that the woman might try to harm the little girls.  She had been re-united with the girls just a few days ago.