The MP for the area said there were “walking wounded” after the fire at Treforest Industrial Estate.
Emergency services remain at the site of a huge blaze at an industrial estate in south Wales with one person still remaining unaccounted for.
South Wales Fire and Rescue Service said the fire is now largely out, with small pockets remaining.
Stephen Davies, who was at a nearby gym in Pontypridd, Rhondda Cynon Taf, said “it was carnage”.
Images on social media in the aftermath showed a building in flames and smoke at Treforest Industrial Estate.
Police said there were no reports of serious injuries but the MP for the area said there were “walking wounded”.
At least one building has been destroyed and a “major incident” was declared for several hours following the “massive explosion” at 19:00 GMT.
The fire service said a two-storey building was “at risk of collapse” and it had seven pumps at the scene, along with an incident command unit.
Some roads in the area remain closed and a joint investigation with South Wales Fire and Rescue Service, South Wales Police and the Health and Safety Executive (HSE) is taking place into the cause.
Mr Davies said: “We were going about our usual gym class and then about quarter past seven we sat down and we had a coffee in the cafe area, the next thing we knew a massive explosion.”
He said he and his friend saw the stairwell by the entrance to the cafe explode.
“All the walls caved in, it was carnage… it was very scary”.
“The staff were excellent in terms of getting everybody out, shouting and making sure everybody escaped out the back entrance.
“It’s a bit surreal, because you are sort of in something, you don’t actually realise how life and death that was.
“You don’t think it’s ever going to happen to you.”
The Welsh Ambulance Service said it “treated three patients at the scene before discharging them” on Wednesday evening.
South Wales Police said there were no reports of serious injuries but “one person remains unaccounted for”.
The force said on Wednesday: “Residents living nearby are advised to close all doors and windows while this incident is continuing.
“Businesses in the area are requested to implement their own business continuity plans to deal with the on-going road closures.”
The fire is in a 60,000 sq ft (5,574 sq m) warehouse called Rizla House which houses 13 commercial units including a gym, a towel manufacturer, a food laboratory and a telecoms service company.
Pet store PetWise, which is based in the building, said on its Facebook page that staff had been escorted into the building to check on the animals and they were all safe and well.
The animals have now been fed and watered.
Cwm Taf Morgannwg health board had put all its emergency departments on high alert for several hours, standing down late on Wednesday.
It also asked people to “continue to make appropriate use of urgent care services to ensure those that most need our care can receive it in a timely way”.
Barber Andrew Cox posted on Facebook that he was trying to work out what the next steps were regarding appointments.
His shop, Andrew Cox Barbering, was in the building underneath the gym where the explosion happened.
“Nobody is allowed near the vicinity so I am completely clueless as to what is still standing, if anything. I am frantically trying to work out what the next steps are regarding all appointments,” he said.
Alex Davies-Jones, MP for Pontypridd, spoke to Radio Wales Breakfast on Thursday morning and said it was a “very significant fire” with a subsequent explosion in one of the businesses.
She added: “We had a few people who were walking wounded due to some debris from the site, from the explosion and the fire, but thankfully at the moment it looks like we’ve had no severe casualties and we’re just hoping and praying for that one accounted person that they do become accounted for and that’s what we’re all hoping for today.”
One nearby business owner said her tattoo shop “just exploded”.
Lucy Artiss, tattooist at Sixteen Circles, said she had “lost everything” but all of her colleagues made it out of the building unhurt.
“I feel numb, to be honest. Looks like I’ll need to find a new shop.”
Nearby Integer Telecom, a telecommunication provider, said in a Facebook post its building was destroyed in the explosion, adding: “All our staff are safe and unharmed and business will resume as normal.“
The manager of a nearby Esso garage, Krishnaraj Nadarajah, said he contacted the fire service and shut off pumps at the station.
The 40-year-old described hearing a “massive explosion”.
He said: “It felt like it was an earthquake or something. We went outside and there was a fire starting to build up, it was a huge fire and smoke.”
“The noise was very loud, it was a big explosion. Some of the things fell down in the store, off the shelves.”
Mr Nadarajah called it “very scary”.
Phill Jones from Llantrisant said he was driving along the A473 with his eight-year-old son at about 19:15 when he saw “a really loud bang and a flash of light”.
“There was a big fireball up in the sky. I swerved the car a little bit and my son got quite animated. The way it went up, it was almost as if something had exploded.”
In an update at 01:30 on Thursday, police said the following roads remain closed:
- Tonteg Road between the Upper Boat and Power Station Hill roundabouts
- Severn Road
- Taffs Mead Road
- Taffs Fall Road
- Bridge Road
- Ford Road
The Health and Safety Executive said it was aware of the incident and was making inquiries.
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