The Health and Safety Executive is set to demand a review of risk assessments on the Arsenal stadium project after the collapse of a wall at the site on Ashburton Grove, north London, last week.

The 7 ft wall, part of a neighbouring post office, fell down on Thursday as workers carried out demolition work on the structure. Nobody on the Sir Robert McAlpine project was injured but emergency services were sent to the site as a precaution.

The HSE has launched an investigation into the incident, and is likely to order the contractor to review its risk assessments for the site. Depending on the severity of the fault, the HSE could also issue an improvement notice or close part of the site.

An HSE spokesperson said: “Obviously this incident could have been a lot worse, and hopefully, if there is a lesson to be learned, it can be learned early. We will want to ensure the rest of the demolition work is properly planned, which would involve a review of risk assessments and method statements. Our issue will be with planning, as adequate arrangements should be in place in case anything unexpected happens.”

The spokesperson said that until the investigation was complete, the HSE could not comment on reasons for the incident. He said that there was a possibility that the exclusion zone surrounding the demolition area might need to be widened.