Lessons from Chevron Pembroke explosion says Cameron
David Cameron has said there will be lessons to be learned from a fatal explosion at a Pembrokeshire oil refinery.
The blast at Chevron in Pembroke was a "tragic incident", the prime minister said.
There were some "inherent risks" in the industry, but the company had a good safety record, he said.
Four contractors died in the blast.
They were Julie Jones, 54, of Pembroke, and Dennis Riley, 52, Robert Broome, 48, and Andrew Jenkins, 33, all of Milford Haven.
The explosion at 1820 BST last Thursday occurred while a storage tank was being taken out of service for maintenance, the company said.
Chevron, which has flown in experts from the US, said the investigation would be a "lengthy process".
Asked by Carmarthen West and South Pembrokeshire Tory MP Simon Hart if he would endorse Chevron's safety record to date, Mr Cameron described the explosion as a "tragic incident".
Speaking during Prime Minister's Questions on Wednesday, he added: "I am sure there will be lessons to learn but as you said it has had a good safety record and a good safety record in an industry in which there really are some inherent risks."
A fourth man is still being treated at a specialist unit at Swansea's Morriston Hospital.
Carmarthen West and South Pembrokeshire Assembly Member Angela Burns has said finding the cause of a blast was "crucial".
She also said she was "very uncomfortable" with some rumours circulating about what happened.
"What is crucial is that we understand exactly what happened, learn from and implement any lessons that we can and also ensure that those lessons are communicated to the wider sector so that we can have the best possible practice in all of the energy industries based on the Haven," added the Conservative AM.