NO criminal charges will be brought against a Cardiff-based steelworks after an explosion in 2015 left two workers dead.

Mr Peter O’Brien a father of six from Cardiff and Mr Mark Sim a father of two from Caldicot died when an explosion occurred at the rod and bar mill of the Celsa steelworks in Cardiff.

Mark Sim, 41, pictured right, was one of the two workers unaccounted for after the blast in Celsa Steel UK’s plant in Cardiff hospitalised four and left two workers missing.

Five other people were injured in the blast, which happened in the basement of the steelworks in Splott, Cardiff at approximately 10.30am on 18th November 2015.

A HSE spokesperson said: “The Health and Safety Executive now has primacy for the criminal investigation into the explosion at Celsa Manufacturing UK Ltd in Splott, Cardiff, on 18th November 2015.

“We fully supported South Wales Police following this incident. Now that we are in the lead, HSE will be responsible for liaison with the families of Peter O’Brien and Mark Sim.

“We have assured them, and indeed make it clear to all affected by this incident, that our investigation will be a thorough one, while also recognising the desire for a speedy conclusion.”