It's an anniversary no one wants to observe. But there is no escaping the memories of December 9, 2011 when 93 patients at the AMRI hospital in south Kolkata were virtually gassed to death in their hospital beds. A fire in the basement sent noxious smoke surging through the air conditioning ducts. The building was centrally air conditioned and there was no outlet for the fumes. The hospital had no means of evacuating patients and by the time the staff realized the gravity of the situation, it was too late.