She spoke in a hushed voice and had a slow reaction time in tests.

One common form of the pills - benzodiazepines - can interfere with chemicals in the brain known as neurotransmitters which could slow reaction times and dull brain power.

Drivers (and their family) have a duty to be aware of factors that may impair driving, such as memory loss, poor concentration, confusion, slow reaction times and loss of confidence.

That could partly explain the slow reaction of emergency vehicles: the fire trucks took at least 90 seconds - a lifetime in high emergency - to reach the blazing aircraft.

This was the major cause for the initial slow reaction by doctors, who did not promptly recognize the symptoms of the disease.