PA MediaThe firefighters who died in a blaze at Bicester Motion have been named as Jennie Logan and Martyn Sadler, while the member of the public who died is David Chester.
Police said both firefighters worked at Oxfordshire Fire and Rescue Service and Mr Sadler was also part of the London Fire Brigade.
Ms Logan, 30, and Mr Sadler, 38, died after explosions were heard at Bicester Motion on Thursday, Thames Valley Police said.
David Chester, 57, from Bicester, was also killed, the force added.
Two firefighters sustained serious injuries and remain in hospital, Oxfordshire County Council said.
At the height of the fire, 10 fire crews were tackling the blaze.
The police have commenced an unexplained death investigation, but are not currently treating it as a criminal matter.
Assistant Chief Constable Tim Metcalfe described it as “an absolute tragedy” and said the thoughts of everyone at Thames Valley Police were with the families, friends and colleagues of those who had died.
The force confirmed that officers will remain at the scene for a number of days to ensure the public remain safe.
PA MediaAt the scene today, a visibly emotional Chief Fire Officer Rob MacDougall said he spoke with “a heavy heart” when he confirmed the deaths.
He added: “Our thoughts are with the family friends and colleagues affected during this time.
“I’m immensely proud and grateful for the exemplary multiagency response and the unwavering bravery demonstrated by the emergency services personnel.”
In a statement, London Fire Brigade said it was “devastated by the loss of our colleague”.
“We are working closely with our counterparts in Oxfordshire, providing support to the family and our crews affected by this tragic loss,” it said.
“Our sincere condolences go out to Oxfordshire Fire and Rescue Service who also sadly lost a firefighter at this incident, with a further two colleagues in hospital.”
Paying tribute, Prime Minister Sir Keir Starmer said his thoughts were with the families and friends of those who had died following the “devastating news”.
He said: “The bravery of our firefighters is astounding. Hoping those in hospital make a full and swift recovery.”
Conservative Party leader Kemi Badenoch described it as “an absolutely horrifying incident”, adding: “I hope that we can get to the bottom of exactly what’s caused this and make sure that it doesn’t happen again.”
Sherine Wheeler, chief executive of the Fire Fighters Charity, told BBC Radio Oxford everyone in the firefighting community was feeling “heartbroken”.
“It’s very rare and tragic to have the loss of two firefighters alongside a member of the public and I think the impact of that is being felt deeply,” she said.
“For a lot of people who serve in the fire service it brings the reality of the risks they hold crashing home.”
