School cleaner critical after stair fall

A 55-year-old man is fighting for life in hospital after being discovered slumped at the bottom of a stairwell at a western Sydney high school.

The school cleaner was found at the base the concrete steps at Plumpton High on Thursday morning, having suffered head injuries before going into cardiac arrest.

A helicopter landed at the school with CareFlight's critical care specialist team tending to the man, who was then transferred by road ambulance to Westmead Hospital in a critical condition.

The man's condition is listed as critical but stable, a hospital spokeswoman told AAP.