Shomrim, the fire brigade, the ambulance service and police rushed to the scene after a building partly collapsed on Brent Street in Hendon on Monday afternoon.
The London Fire Brigade said a brick fascia above a single-storey pair of shops, which was about 20 metres long, had fallen to the ground.
The owner of one of the stores affected told the JC it was a "freak accident".
Watch footage from the scene below
Shomrim, the volunteer Orthodox neighbourhood watch group, was called at 12.53pm to "reports of a partial building collapse" and helped evacuate the scene until emergency services arrived.
Footage from the scene shows kosher deli staff helping people evacuate.
No one was injured, the London Fire Brigade said.
The area was cordoned off and shops were evacuated.
Shani Grunhut, who owns The Wardrobe, a boutique clothing store for religious women and one of the four shops affected, called it a "freak accident".
Mrs Grunhut told the JC that at the time she was not in the shop that she has been running for more than a year, but that a member of staff was there with three customers.
"Thank God nobody got hurt," she said. "My worker likes to talk to the customers so fortunately they were inside with her and not outside the shop.
"We had a lot of people from the Kosher Deli and from different stores helping the women to get out.
"I don't really know what happened... it was a complete freak accident. Something came loose, like a beam, and I think that everything else that was fixed and supporting it just crumbled down.
"No one was on the street at the time which was amazing, and it was also during lunchtime which gets very busy."
The Wardrobe was one of four shops affected, including a pharmacist, a hairdresser and a glazing company.
Mrs Grunhut said that her business is closed while measures are being taken to secure the site, but added: "I'm hoping that it won't be more than a week."
Another witness told the JC she heard a "loud rumble" and looked out of her office window to see the devastation.
Brent Street was closed in both directions while the area was secured.