A group of schoolchildren watched in horror as a teacher toppled backwards 20 feet into a road when a safety railing gave way.
The woman, believed to be in her 30s, landed on her back and head in Church Lane, Harbledown, near Canterbury.
Two ambulances attended and paramedics spent nearly an hour treating and stabilising her before she was taken to hospital.
A teacher plunged 20ft when a railing gave way
Now an investigation is under way into why the metal rail failed on the footpath high up over the road outside St Michael's church.
Demolition worker Stephen Stanbury, 38, who lives on the nearby London Road estate, was in his van opposite the church and witnessed the fall.
He said: "I was rolling a cigarette and watched the group of about seven children walk up the slope with what looked like two teachers.
"They stopped at the top and a few sat on the bench outside the entrance to the church.
"One of the adults then just perched on the metal rail with her back to the road. She sat down gently and wasn't jumping up and down.
"But it just gave way and she somersaulted backwards and landed on her back and head.
The woman landed on her head and back
Mr Stanbury added: "It looks like a sturdy rail, but a joint seems to have just given way, so it was pretty dangerous.
"I couldn't believe it. It was horrible to watch because she landed with a hell of a bang.
"It looks like a sturdy rail, but a joint seems to have just given way, so it was pretty dangerous..." - Stephen Stanbury
"I just got straight on my phone and dialled 999 because she looked badly hurt.
"I was told she was a teacher and it was obviously pretty distressing for the children who saw it.
"She was still conscious but a bit drowsy and, together with the other teacher, I helped comfort her and hold the traffic back until the ambulance arrived.
"They were treating her at the scene for nearly an hour and I think they were worried about her back injury.
"I just hope she is going to be all right."
Schoolchildren watched in horror as the drama unfolded
The rector of St Michael's, Father Michael Morris, said he saw the ambulance at the scene on Tuesday and thought someone had been knocked off a bike.
He added: "The railing along the path has been there donkey's years and doesn't look in very good repair.
"It's not the church's responsibility, but presumably Kent Highways', and will need to be made safe to avoid another accident."
Toby Howe, East Kent highway manager for Kent County Council, said: "We are concerned to hear about the injuries suffered by the woman involved and our thoughts are with her.
"One of our highway stewards made the railing safe immediately after we were made aware of the issue and barriers are being put in place.
"We will be investigating the cause of this unfortunate incident and what repairs need to be carried out."
An ambulance at the scene of the fall in Church Lane, Harbledown
South East Coast Ambulance Service spokesman Rich Airey said: "We were called to Church Hill in Harbledown just before 2.10pm to reports that a woman had suffered a fall from a five-metre wall.
"We sent two ambulance crews to the scene, and police also attended.
"The woman was suffering from back pain. She was fully conscious and was assessed and treated at the scene before being taken to the William Harvey Hospital."
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