NSW Police are looking at the phasing of traffic lights and say there was no suggestion yet of negligent or dangerous driving in the death of a 16-year-old cyclist at Shellharbour in New South Wales.

Key points: A 16-year-old boy who was hit by a car in the Illawarra died after being airlifted to St George Hospital last night

A 16-year-old boy who was hit by a car in the Illawarra died after being airlifted to St George Hospital last night The driver involved is distraught and fully co-operating with police, who say there is no evidence of negligent driving

The driver involved is distraught and fully co-operating with police, who say there is no evidence of negligent driving Police say no helmet was found at the scene where flowers have been laid in memory of the teenager

The boy was riding his bicycle along Wattle Road near Benson Avenue at Shellharbour in the Illawarra when he was hit at around 6:00pm on Tuesday.

Lake Illawarra Police Acting Inspector Anthony Peterson said there was no suggestion of negligent or dangerous driving and no indication of excessive speed, but crash scene investigators were reviewing the traffic light sequences.

Lake Illawarra Police Acting Inspector Anthony Peterson. ( ABC Illawarra: Ainslie Drewitt-Smith )

"I know that [the] Crash Investigation (Unit] wants to look at the phasing of the lights at the same time that the crash occurred. There are a number of witnesses that have been interviewed," he said.

"He was unconscious the entire time that he was treated by police and ambulance.

"There is no indication of a helmet being present at the scene that he was wearing at the time."

Flowers laid, driver distraught

The teen was airlifted to Sydney Children's Hospital at Randwick in a critical condition, but died during the night.

Flowers have been laid at the intersection where the collision occurred.

Acting Insp. Peterson said the female driver, 25, was distraught and was fully assisting police at this stage.

The intersection where the incident happened. ( ABC Illawarra: Ainslie Drewitt-Smith )

She underwent mandatory drug and alcohol testing following the crash.

The road was partially closed this morning.

The Crash Investigation Unit is investigating the circumstances surrounding the incident.