A company will be prosecuted after two engineers were killed following an explosion.
Father-of-six Peter O'Brien, 51, and Mark Sim, 41, died after a blast in the basement of the Celsa Steel UK plant in Splott, Cardiff, in November 2015.
Five men were also injured in the incident.
The Health and Safety Executive has now told Celsa Manufacturing (UK) it will face a charge under the Health and Safety at Work Act.
Representatives of the company will appear at Cardiff Magistrates' Court on 11 September.
The men's bodies were recovered by a specialist police search unit after the explosion in the basement of the plant's rod and bar mill on East Moors Road on 18 November 2015.
Fellow workers held two minutes' silences for their colleagues, including on the first anniversary of the explosion.
Mr O'Brien, of Llanishen, Cardiff, was described as a "kind, gentle and funny man" who loved the outdoors and camping by his wife Marie and their six children.
They said he played a "major part" in the church and community and was a respected rugby player and award winning bowls player for St Peter's Bowls Club in Cardiff.
Mr Sim was originally from Newcastle but lived in Caldicot, Monmouthshire.
After his death, his wife Samantha said in a statement: "I will cherish time we had together, the laughs and parties because Mark loved a good party - always the last one to leave.
"Mark will leave a big hole in our hearts and a great void in the lives of his daughter Georgia and son Jackson and to everyone's lives that he touched."
A spokesperson from CELSA Steel UK said: "On November 18th 2015 Celsa lost two of our friends and colleagues, Mark Sim and Peter O'Brien.
"That day, and the week that followed, will be remembered as the most difficult and tragic week in the history of Celsa Steel UK. While we know that nothing we can do will ever bring Mark and Peter back, or atone for their loss, we are doing everything we can to support their families going forward.
"It would not be appropriate to comment further at this stage."