It Was 2012. Me & My Wife Were Traveling By Puri-Howrah Duronto Exp [ Now Runs As Shatabdi Exp] , Coach No C-4. After KGP, Poisonous Gas Started Coming Out Of AC Vents And In A Flash Entire Coach Was Full Of Gas. Immediately I Pulled The Chain And Train Took Few Seconds To Come To A Halt. All The Passengers Were Shifted To C-3 & C-5.... And Doors Of The Coach Were Kept Open... Reached HWH In That Condition Only