POLICE suspect speed contributed to an accident in which a teenage girl was killed when the car her boyfriend was driving plunged into a river.

Danni Thomlinson, 15, was the only passenger in the car when it went through a railing and off a bridge, plunging into the Williams River at 8.30pm on Friday.

Rhys Mcgrorey-Clark, 18, freed himself from the driver’s seat of the Daewoo and swam to the riverbank but by then the car had sunk.

Police said he made many attempts to dive into the river at Raymond Terrace, 22 kilometres north-west of Newcastle, to free his girlfriend. Guests at a nearby caravan park, who had watched the incident unfold, also ran to his aid. They were unable to reach the car as the water was too deep.

Port Stephens acting Superintendent Brian Larkham said that, while police were still trying to determine what happened, ‘‘our initial investigations suggest speed may have been a factor’’.

Police recovered the Raymond Terrace teen’s body early yesterday.

Locals said the bridge was not a notorious trouble spot and it had not been raining at the time of the incident, though it had been wet earlier in the night.

Friends of Danni, who attended Irrawang High School and worked at her local McDonald’s were last night planning to hold a gathering to remember her.

Jaimii Doyle, a friend who worked with Danni, said she had a bubbly personality. ‘‘She was a lovely girl. She was always very nice,’’ she told Channel Seven.

Mr Mcgrorey-Clark was taken to Newcastle’s John Hunter Hospital in a stable condition and was being treated for shock.