Ah. Thats where the problems arise. What are reasonable measures? Back to the passengers on the Clapham Omnibus and M'Lud.
In deciding what is reasonable is it not common to measure one against ones peers? And if M'Lud did this, even in the aftermath of a disaster, is he likely to find Mrs Postlethwaite wanting for not providing adequate evacuation lifts in her building? Especially as it could have been built fully in accordance with Building Regulations and subject to all consultations with every statutory authority along the way? I think not. Look at the Hillsborough Disaster. The football club were not found wanting for failing to provide exits forward to the pitch although this would have saved many lives. The club were measured against current standards and their peers and not individually castigated for this.
You cannot expect anyone to install evacuation lifts retrospectively unless as part of a very significant refurbishment. But put someone behind two fire doors and one hours walls and floor away from the fire, accompany them and keep in communication and then when the time is right offer them the necessary assistance to select use the route out of the building least likely to harm them, taking into account all hazards including fire, falling, or injury caused by being manhandled. This may be a standard passenger lift, a fire appliance, an evac chair, a dining chair or carry them in their own wheelchair.