Sources?
I get the impression that this article needs more work. What's with there only being one general reference? (The "United States Holocaust Memorial Museum Encyclopedia entry", the other one being specifically about the female guards) The article's content doesn't even seem perfectly match the information of this one reference: 

USHMM: In early 1945, the SS constructed a gas chamber in Ravensbrück near the camp crematorium. The Germans gassed between 5,000 and 6,000 prisoners at Ravensbrück before Soviet troops liberated the camp in April 1945. 
Wikipedia: In the autumn of 1944, the SS constructed a gas chamber near the crematorium. The Germans gassed several thousand prisoners at Ravensbrück before the camp's liberation in April 1945. 

Also, the link to the mercurynews.com article is dead.