Two children, aged one and six, and their mother have died in a fire at their mobile home.
The 35-year-old woman's husband and their eldest son were also treated for burns following the blaze at The Plantation in West Park Road, Newchapel, Surrey, during the early hours of this morning.
The woman's husband, who is also 35, was treated for burn injuries at the location and their 10-year-old son was taken to East Surrey Hospital as a precaution. He has since been discharged.
Ian Ray, assistant group commander of Surrey Fire and Rescue Service, said that although the incident had been scaled down the cause of the fire was still under investigation.
The privately-owned site, used by members of the Showmen's Guild of Great Britain - travelling showmen who make their livelihoods through funfairs - was in mourning today following news of the deaths, Guild president David Wallis said.
The 70-year-old said he knew of the family and that the man and woman had been married for "quite some time".
He added: "It's a terrible thing and all the members of the Guild throughout the country send their condolences out to the family."
Mr Wallis said the Guild's benevolent fund would take care of the financial side of things and that two representatives had gone to the site to help in any way they could.
He said he had received phone calls from members across the country offering help.
He said: "What can you do when there are children involved?
"We are a travelling fairground community, a regulated body and very well organised and accepted throughout the country.
"We are quite a close community and the families living on the site are all very close and will be looking after those affected."
Three crews from Surrey Fire and Rescue Service were called to the blaze at 1.37am.
A fire service spokesman said: "Sadly, two children and one woman have died.
"Surrey Fire and Rescue Service and Surrey Police are carrying out a joint investigation and our thoughts are with the family and friends of those involved at this tragic time."
Surrey Police said: "A 35-year-old man and a 10-year-old boy were also treated for burn injuries at the location. The child was taken to East Surrey Hospital as a precaution and has since been discharged."
The police also said units were at the scene, which remained cordoned off while inquiries were carried out into the cause of the fire.
Police guards stood at entrances to the mobile home site, which is beside a busy main road.
Fire engines also remained at the scene as officers stood blocking a public footpath running alongside the site.
A Tandridge District Council spokesman confirmed that the site was privately owned and had been operating on the land for more than 20 years.
He said: "Tandridge District Council is aware of the tragic fire at The Plantation early this morning in which an adult and two children sadly lost their lives.
"We would express our sympathies to other members of the family.
"Tandridge District Council has no role in the management of the site, which is in private ownership.
"We understand that the fire and police services are currently investigating the circumstances of the fire.
"The council has no direct involvement in this investigation but will assist if our services are required in any way."