Still more jealous bitterness was engendered by the O ' Banion gang's seizure from a West Side marshalling yard of a freight-car load of Canadian whisky worth $100000 and by one of the biggest coups of the Prohibition era -- the Sibley warehouse robbery, which became famous for the cool brazenness of the operation. Here was stored $1000000 worth of bonded whisky. These 1750 cases were carted off in a one night operation by the O ' Banion men, who left in their stead the same number of barrels filled with water.