A company has accepted a health and safety breach over an explosion which killed two engineers in the basement of a steelworks factory.

Dad-of-six Peter O’Brien, 51, from Llanishen, Cardiff, and father-of-two Mark Sim, 41, from Caldicot, Monmouthshire, died at the Celsa steelworks plant in Cardiff.

Cardiff Crown Court was told on Tuesday that Celsa Manufacturing Ltd was being prosecuted by the Health and Safety Executive after allegedly breaching health and safety laws relating to the equipment involved in the blast on November 18, 2015.

Mr O’Brien and Mr Sim were employees at the factory where scrap metal was turned into steel used to reinforce concrete. A third man, Darren Wood, was injured in the blast.

(Image: Media Wales)

The case was due to go to trial on Wednesday but the firm, through a QC, pleaded guilty to a new charge of "failing to make a suitable and official assessment of risks” in relation to the three men.

The prosecution, brought by the Health and Safety Executive, requested that an earlier charge – which Celsa had denied – be allowed to lie on file.

The sentencing hearing will take place on October 4.

Recap what happened in court: