The Health and Safety Executive (HSE) will now lead the investigation into the two deaths at Teesworks in 2019 after the safety watchdog and Cleveland Police did not find enough evidence to pursue gross or corporate manslaughter charges.
John Mackay, 49, from Edinburgh, and Tom Williams, 65, from Warwickshire, died on 19 September 2019 following an explosion at the former SSI UK steelworks site in Teesside, now called Teesworks.
The two men were employed by demolition contractor John F Hunt and plant hirer Nationwide Platforms. They were working at height removing external steel furniture from a storage tank when the blast happened.
It took firefighters a week to retrieve their bodies from the platform and Mackay had to be identified by dental records.
The Teeside plant was the former site of Thai-owned Sahaviriya Steel Industries (SSI UK). The operator entered liquidation in 2015, resulting in the loss of around 2,000 jobs.
The site then became part of the South Tees Site Company, a joint venture between the government and the South Tees Development Corporation.
John F Hunt held a £100,000 contract to demolish the ammonia washers when the explosion happened.
HSE principal inspector John Heslop said: “Although some of these developments are difficult for the families of John and Tom, I have assured them that the criminal investigation into their deaths remains ongoing. We also made it clear our investigation will be a thorough one, while also recognising the desire for a speedy conclusion.”
The family of Mackay said they intend to challenge the decision not to pursue gross or corporate manslaughter charges, the BBC reported.
