Editing Revolving door (section)

== Emergency use ==
On November 28, 1942, the [[Cocoanut Grove fire|Cocoanut Grove]], a popular nightclub in [[Boston]], Massachusetts, went up in flames, killing 492 people. One of the main reasons cited for the large number of casualties was the single revolving door located at the entrance. As the mob of panicking patrons attempted to use the door as an escape it soon became jammed, trapping countless people between the door and the crowd pushing towards it. As a result, many people died from [[smoke inhalation]], as they were not able to escape the burning nightclub.

In 1943, it became a Massachusetts state law requirement to flank a revolving door with an outward swinging hinged door or to make the revolving door collapsible (so it becomes a double partition collapsing at 180°), allowing people to pass on either side. American revolving doors are now collapsible. Some jurisdictions require them to be flanked by at least one hinged door either by common practice or required by law. For example, the [[Ontario]] [[Building code|Building Code]] 3.4.6.14. asserts that revolving doors needs to "(a) be collapsible, (b) have hinged doors providing equivalent exiting capacity located adjacent to it".<ref>[http://www.e-laws.gov.on.ca/html/source/regs/english/2006/elaws_src_regs_r06350_e.htm ONTARIO REGULATION 350/06 made under the BUILDING CODE ACT, 1992]</ref>