As the world has evolved, so too have the requirements for emergency medical equipment, and one of the most vital pieces of lifesaving equipment over the past four decades has been the evacuation chair.
Not only is it a legal requirement for all buildings to have a safe means of escape for disabled people, but as skylines get taller, buildings become more dependent on disabled access solutions that are not safe to use in an emergency.
This realisation first dawned on the late David Egen, who learned how much the emergency evacuation world had changed when his wife faced a terrifying situation in 1980.
Maureen Egen, a publishing executive and survivor of childhood polio, was forced to evacuate from her office on the 38th floor of a building, which, due to partial paralysis, was extremely difficult. Ultimately, her coworkers helped to get her out safely, and fortunately, the emergency was a false alarm.
When this happened a second time, Mr Egen decided to fix this by developing a chair that could be moved by a single person safely downstairs, which ultimately became a hybrid of hand trucks used to lift heavy appliances, stretchers and wheelchairs.
The result was a cart that was four times faster than any traditional carry system, only required one person to work, and was significantly safer, smoother and more controlled than any alternative exit system that had been proposed, from stretchers to traditional two-person carry options.
It was described as a lifeboat for skyscrapers, as it was lightweight, adjustable, and easy enough to use that someone without significant training could use it safely.
It was designed in the early era of accessible design, but has only become more important than ever before, as the Disability Discrimination Act 1995 and later the Equality Act 2010 meant that building owners could be liable if someone was harmed because there was a lack of suitable equipment to safely evacuate them.