The street resembled a bomb scene. Casualties were lying in the road and debris was scattered 150 metres.

Police tried first to help the casualties but were aware of a second vital task - to preserve evidence. If a crime had been committed, they would require as much as possible to prosecute the guilty.

Earlier this year Graham Travers, the drink-driver responsible for the deaths of two nursery nurses in the crash, was sent to prison for five-and-a-half years, a sentence the victims' families believe was far too lenient.

Travers had bullied the worried women into getting into his car.

After the crash he gave no explanation, showed no remorse and said nothing to police during interviews.

However, once his defence team had been shown the mountain of evidence stacked against their client, he threw in the towel.

He pleaded guilty at Lewes Crown Court to drink-driving, driving without insurance, driving without a licence in someone else's car and killing Natalie "Flo" McCabe, 21, of Ravensbourne Road, Shoreham, and Vicki Browne, 19, of Bentham Road, Brighton. Their friend Becky Fish, 20, of Mile Oak, lost a leg and damaged the other.

The guilty plea meant hardly any of the evidence police had prepared was put before the court. Sussex Police agreed to release some of that evidence to The Argus to demonstrate how far they went to secure a conviction.

The investigation was headed by Inspector Simon Labbett, in charge of the road policing unit in Hove.

By the time he was eventually ready to take the case to court, more than 70 witnesses were on standby to give evidence.

Travers, 21, a barman, of Shelldale Road, Portslade, had been working on the day of the crash at a pub in Rutland Road, Hove. At about 7pm he asked a friend if he could borrow his Ford Mondeo to take his girlfriend home but the couple had an argument and she went home alone.

The nursery nurses were enjoying an evening together in a pub in Hove.

Travers mingled with the group and persuaded them to go to the Portland pub in Portland Road. Becky Fish later told police she was reluctant to go in his car, being worried about the speed and the noise from the car's engine.

The friends wanted to go home at 11pm and Travers, who had been drinking all evening, said he would give them a lift.

Ms Fish recalled Travers, who had never held a valid driving licence, being cross and agitated. She was hesitant but Travers ordered them: "Get in the car."

She said Travers put his foot down on the accelerator so hard her head was jolted back.

She told officers: "I was very scared."

Witnesses saw the Ford Mondeo speeding without lights and at between 70 and 80mph along Portland Road, a 30mph zone. As the car reached the junction with Coleman Avenue, it passed over a dip, causing twisting on the rear suspension.

Mr Labbett said: "The vehicle became unbalanced and, with the driver struggling to retain control, the vehicle crossed the carriageway where it initially struck a kerb, sign and lamp post."

A rear door was torn off and the car took off and gyrated, landing on a parked Ford Sierra which was pushed 40 metres along the road.

The Mondeo landed on its roof and slid 23 metres before stopping.

Mr Labbett said Travers clambered through the front passenger window, pushed past a witness and showed no regard for the victims he left behind.

Travers was seen by a witness on a staircase in nearby flats, bleeding from an arm wound. Police arrested him and he admitted being the driver - but those were the last comments he made to officers.

As police family liaison officers made contact with next of kin, other officers were at the Royal Sussex County Hospital.

They took blood samples and glass fragments which had been embedded in Travers' arm and later matched them with glass and blood from the Mondeo.

Collision investigators and scenes-of-crime officers worked at the crash site, aware the road needed to be reopened as soon as possible.

They were initially confused by three blood trails leading from the vehicle.

It emerged that, by coincidence, a friend of Travers had severed an artery the night before and had crossed Portland Road at the very spot the car came to rest.

One of the trails was from Travers.

Officers gathered evidence from police and shop CCTV cameras in Portland Road to establish direction and an estimate of the Mondeo's speed.

They set up a video reconstruction and closed part of the road to show how a vehicle would react travelling in such circumstances. The car "twisted" at 60mph.

The impact dynamics of the collision were complex and involved several tyre scuffs and scratches, which had to be examined.

To explain concisely to a jury what happened to the Mondeo would have been difficult. Police instead created a 3D computer-generated animated film.

They were worried not just by technical matters but also by emotional concerns.

Mr Labbett said: "The investigation was conducted in an atmosphere of high-level media and public interest."

He said there was considerable hostility against Travers and there was a risk of someone trying to harm him.

He was kept in custody throughout the build-up to his trial.

Meanwhile, police obtained what they termed an "extensive and emotionally-charged" account of events from the only other survivor, Ms Fish.

Police and the Crown Prosecution Service worked together, slowly building the case and held a meeting with the bereaved families before the trial opened.

Mr Labbett said: "Relationships with the families remained good, although with some it was very clear the police could only get things wrong. This was a tightrope relationship and, thankfully, balance was successfully maintained."

As it turned out, much of the evidence remained unheard in court after Travers pleaded guilty on February 11 this year.

The investigation took six months and involved 70 witnesses.

Road police officers from Chichester, Bexhill and Haywards Heath were brought in to assist their Hove colleagues.

Thousands of police hours were devoted to the case.

Mr Labbett said: "Sussex Police annually investigate about 100 fatal collisions. This was one of the most horrific in the memories of the investigators."