A huge pillar plunged 10 storeys from the top of a construction site in De Beauvoir where Hackney New Primary School is being built – narrowly missing a woman driving a Mini.

The driver was waiting at the traffic lights in Downham Road at the junction with Kingsland Road when the massive concrete rod tumbled off, landing yards from her car.

The Health and Safety Executive has been called in to investigate the accident, which happened at the former Kingsland Fire Station site being developed by the Benyon Estate, developer Thornsett and the Department for Education.

Kapil Gupta was in his flat opposite when he heard a "huge thud" as the pillar landed on the ground.

He told the Gazette: "It was like some kind of a crash, and I looked out and there was this pillar covering the road. There were five or six cars at the junction, and one of them belonged to a lady who was quite traumatised.

"All the other cars drove off at the traffic light, but she stayed there, probably for about half an hour.

"It looked like she was shaking and there was someone from the building site by her side and calming her down. She stood outside the car for a while, and then one of the guys from the building site asked her to go back into the car. There were a few security people from the site talking to her and making sure she was ok.

"There was a big dent in the road but they have patched it up now."

Mr Gupta speculated on what could have happened: "I believe they were mounting a pillar on the top of the building, and it wasn't fully secured," he said. "They were in the process of making sure it was locked in place, and it slipped or something happened, and it fell through the scaffolding on the road."

He added: "I don't know what kind of health and safety procedures they are following, but the way it fell it damaged some scaffolding on the side of the building, so people working on the site could have easily been hurt by it.

"It is a scary thing. We walk next to that development under the scaffolding every day. It's one of those things you where you think: 'Oh wow. Things like this can happen at any time.'"

In a statement, the directors of Thornsett Structures Limited - Bernadette and Gerald Cunningham - said the accident involved one of their specialist subcontractors.

"The incident has been reported to HSE and a detailed investigation will be carried out," they said.

Hackney New Primary School first operated out of the Hackney New School secondary, opposite the building site, when it opened in 2015. It moved to temporary buildings further down Downham Road two years ago. The new site is supposed to be ready for pupils by September. Developers stand to rake in millions of pounds from the sale of 68 full-price flats above the school.

The Benyon Estate, Hackney Council and the HSE have yet to comment.