Gas chamber Gas chamber A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. The most commonly used poisonous agent is hydrogen cyanide; carbon dioxide and carbon monoxide have also been used. Gas chambers were used as a method of execution for condemned prisoners in the United States beginning in the 1920s and continue to be a legal execution method in three states. During the Holocaust, large-scale gas chambers designed for mass killing were used by Nazi Germany as part of their genocide program.
Multistorey car park term open parking garage to refer to a structure designed for car storage that has openings along at least 40% of the perimeter, as opposed to an enclosed parking garage that requires mechanical ventilation. Natural or mechanical ventilation provides fresh air flow to disperse car exhaust in normal conditions, or hot gas and smoke in case of fire. Typically car park experts describe the number of car park floors in terms of "G+x". G stands for ground and x for the number of floors above ground. For example, G+5 is a multi-story car park structure with a ground floor and