Azra Kemal, 24, was driving down the A21 in Kent after a night out with friends at around 2.30 am on Thursday when smoke started coming out of her engine.

The law graduate from London and a friend she was with got out of the way when the car suddenly exploded.

As they tried to flag down traffic from the opposite carriageway of the Medway Viaduct, Ms Kemal climbed over the barriers in the dark, thinking there would be a central reservation.

Instead she fell through a gap and plunged 40 feet to the ground below. Her mother Nevres Kemal, 56, said she initially survived the drop and that her friend jumped after her but couldn’t find her.

She says an off-duty nurse was passing by, saw the car and called the paramedics, but despite their best efforts she was pronounced dead at the scene at 3.20am.

Ms Kemal said her daughter’s last words were ‘Please don’t let me die’ as her rescuers tried to save her. The social worker told the Daily Mail: ‘She was really and truly the air that I breathe. That is all I live for, for her. I am in total shock. I do not know what to say.

‘She had friends from North, South, East and West. She did not have postcodes. She bridged that gap. She came good. She was such a giver, she was so bright and feisty.

‘What I have heard from all her friends is that Azra would give love and try to help. She was no angel but she had that quality. There was no judgemental bone in her body.

‘She was my world. I can’t cry anymore. She doted on me and I doted on her. She was a beautiful soul. She always used to say: “I am an old soul”.’

Ms Kemal is now calling for lights or signals on the bridge so similar tragedies can be prevented in the future.

Having graduated from the London School of Economics, Ms Kemal was due to start her law practice course this year. Her 31-year-old friend was initially arrested at the scene as police tried to establish what happened, but he was later released without charge.

A Kent Police spokesman said: ‘Detectives investigating the circumstances around the death of a woman who fell from a bridge on the A21 are satisfied there are no suspicious circumstances and are now preparing a report for the coroner.

‘The woman, who was 24 and from London, is understood to have fallen while seeking assistance after a car she was travelling in caught alight.’

Investigators are urging anyone with dash-cam footage of the incident to come forward.