One dead in NSW school bus crash

SYDNEY - One man is dead, a woman is fighting for her life and a busload of school children and their driver have been taken to hospital following a crash in Sydney's south.

Eleven ambulance crews and two helicopters rushed to Heathcote Road, near the junction of New Illawarra Road, at Lucas Heights about 9.50am NZT on Friday after reports of a collision between at least one car and a school bus.

Tearful children suffering various injuries were helped through the broken windows of the bus, which had been en route to Sutherland Shire Christian College, and about 40 students have now been taken to Sydney hospitals.

The NSW Ambulance Service said 11 of the children were in serious conditions, contradicting police reports just five children were injured and that their injuries were minor.

An ambulance spokeswoman said the bus driver suffered serious injuries, while the 40-year-old female passenger of the silver sedan was critically ill with head, chest and leg injuries.

Once released from the car, she was airlifted to St George Hospital.

Her male companion died at the scene.

A witness said the two cars had been travelling in opposite directions on a hill section of Heathcote Road when the crash occurred.

"Then a car was travelling east and for no apparent reason seemed to go on to the other side of the road and just directly into the side of the bus, the front, left hand side, right where the (bus) driver was," she told ABC Radio.

"We had to smash the side window to get access straight away and to get a couple of people into the bus just to access what was going on."

She said older kids comforted the younger ones: "It was very calm considering all things."

Sutherland Shire Christian College principal Nicola Taylor told Macquarie Radio she had been in contact throughout the morning with her co-principal, Andrew Middleton, who was at the scene.

"On the bus would only be students represented from the junior school, that's K to six," she said.

"We did have secondary students on the bus. We have a bus monitor system so some of our senior students act as bus monitors and were there to care for the younger students as part of their bus travel duties."

Ms Taylor said the emergency service personnel were very quick to respond and the school was "very thankful and appreciative".

The school has contacted all the parents of the children on board the bus.

The cause of the accident is still under investigation but police said it did not appear as though speed was a factor.

They have confirmed it was a head-on collision but said blame had not yet been attributed to either driver.

Heathcote Road will remain closed all morning.

- AAP