Concerns were raised about the Basi Construction Limited development in High Halstow last January after both Southern Water and Medway Council saw work was underway down a three metre deep excavation into soft clay that was totally unsupported.

Two plywood sheets and a single strut had been added when they returned to the site a day later.

A subsequent HSE investigation saw Basi Construction in court for failing to properly plan the excavation, and for endangering workers by leaving unsupported sidewalls that were liable to collapse.

Chatham Magistrates’ Court heard the excavation had been made to connect a single new-build home to an existing sewer, with an agent employed by Southern Water visiting the site to check the connection.

An employee from the highways department at Medway Council visited separately in response to complaints about work in the footpath outside the site.

The employee notified HSE and described in detail what they had seen, including someone climbing from the excavation. Tools and equipment could also be seen at the bottom.

The excavation had been backfilled by the time a HSE inspector arrived on site – but the witness evidence proved damning.

Magistrates were told that although there was no excavation collapse and no injuries, workers could have been killed had the clay sidewalls given way.

Basi Construction of Rochester, was fined £8,000 and ordered to pay £8,797 in costs for a single breach of the Construction (Design and Management) Regulations.

After the hearing HSE Inspector Melvyn Stancliffe said: “It was pure good luck that the excavation didn’t collapse, and had it done so anyone working at the bottom would have more than likely been killed before they could be rescued.

“Before any excavation begins contractors must ask themselves: ‘What will the consequences be if this fails? And what precautions do I therefore need to put in place to prevent that from happening?’

“Sidewalls may look solid, but an unsupported wall will always collapse, and you need to work on the basis that it could give way in the next few seconds, not tomorrow or next week.”