Police investigating an oil refinery explosion that killed four maintenance workers have described it as a “tragic industrial accident”.
Early indications suggest the blast took place in a vast storage tank as maintenance work was being carried out at the Chevron Refinery in Pembrokeshire last night.
Four contractors have been killed and a fifth airlifted to Morriston Hospital in Swansea with serious burn injuries.
Witnesses described an explosion so big it shook the windows of a coastguard station across the water, followed by a fireball in the sky over the plant and a dense column of dark smoke.
Police officers were this morning in the process of informing the families of the workers involved, as a joint investigation with the Health and Safety Executive began.
Chief superintendent Gwyn Thomas, the officer in charge of the incident for Dyfed Powys Police, said emergency services received a call about the blast at 6.22pm.
“Paramedics have confirmed that four people lost their lives as a result of the incident,” he said.
“Officers are now in the processes of informing the next of kin and will support the families throughout this difficult time.
“Our thoughts are now with the family, friends and colleagues of the deceased.
“The fire was a result of an explosion in an 730 cubic metres storage tank whilst maintenance work was carried out. Damage was also caused to an adjacent storage tank.”
Cordons were put up at all access roads leading to the plant, which employs 1,400 people and is one of the largest in western Europe.
Offshore winds dispersed any contaminants released in the blast out to sea and there is not thought to be any ongoing threat from the site to the local area.
Assistant Chief Fire Officer Chris Davies, from Mid and West Wales Fire and Rescue, said: “Members of the public can be reassured that there is no ongoing risk to health
as a result of the incident.”
The Chevron refinery’s general manager, Greg Hanggi, said the accident was “utterly devastating”.
“The loss of our co-workers has come as a huge shock to us all,” he said.
“Our thoughts and deepest sympathy go out to their families. We will ensure that all employees and contractors are fully supported throughout this difficult time.”
“We will take every step possible to determine the series of events that led to this tragic incident and ensure that any lessons learnt from it will be integrated into the business and shared with our industry partners.”
The refinery, which processes 220,000 barrels of crude oil a day, was bought by US-based Valero earlier in 2011 for $730m (£458 million).
Another $1bn (£611m) was paid for assets including Chevron’s petrol stations in the UK and Ireland.
Marcus Lutwyche, owner of a shop in the village of Angle near the refinery, told Walesonline: “I ran to the front and saw a huge plume of smoke. It was black and filled the sky. It must have been 50 or so metres wide.”