Experts reveal what happens to your brain when you die 

It was just before Christmas in 2009 when Tom Kearney got hit by a bus.

He was walking back from his office in central London, excited to see his children, when a speeding bendy bus mirror smashed into the back of his head, causing a skull injury and pushing him in front of the bus. His head was cracked open and his lungs were burst.

The incident happened as Tom was waiting for the ‘green man’ to cross the road on the south east corner junction of Harewood Place and Holles Street in Oxford Circus. But just moments later, Tom found himself thrown down the street choking to death on his own blood.

He was tended to by a 16-year-old boy, Hamza Benkhadda, who had just completed his first aid training, before being rushed to hospital where he slipped into a coma – and where he had a near deat