TWO towers which saw a fatal explosion at the former Redcar steelworks site are set to be demolished next month.

Families of much-loved grandfathers, John Mackay and Tommy Williams, gathered to pay their respects at the South Bank site on Sunday – a year on from their deaths. 

The pair were killed while working on stripping furniture from the ammonia scrubbers to prepare them for demolition.

Investigations by Cleveland Police and the Health and Safety Executive are still continuing. 

Now leaders at the South Tees Site Company (STDC) have revealed the contract is out for the demolition of the towers with work “expected to commence next month”. 

The three ammonia washer vessels had been taken out of service and removed from the gas stream around 1990.

Documents for a Compulsory Purchase Order (CPO) at the former SSI site stated the towers were facing “uncontrolled” and “imminent” collapse earlier this year in the wake of the explosions.

A report by David Allison, former chief executive of the South Tees Development Corporation, revealed how national action had been triggered in a bid to keep the site safe. 

The paper added: “National resilience services and equipment have been employed to control the hazard and the potential for imminent collapse onto adjacent, equally hazardous, infrastructure.

“Measures have now been put in place to control this through STSC (South Tees Site Company) – further stretching public resources and will continue to do so potentially until October 2020, when a controlled demolition can be completed.”

It is also understood officials were “on call” last Christmas in case of the towers’ collapse. 

But now the South Tees Site Company (STSC) believes the towers are more stable than previously thought. 

A STSC spokesman said: “The towers have remained upright and stable through both a winter and a summer, including gusts of winds of up to 80 miles per hour. 

“As such, there are no concerns over their stability for the foreseeable future. 

“We are now in the process of contracting for the demolition of the towers and expect the work to commence next month. 

“There remains an ongoing HSE and police investigation into the incident and we are not able to comment further.”

The wider former steelworks site is costing about £16m a year to “keep safe” with money set aside for the running costs of STSC until the end of 2022. 

Almost 1,000 acres was brought into public hands at the former steelworks site following CPO hearings earlier this year – with the aim of creating 20,000 jobs in the next 20 years across the vast site.