Neighbours used a sledgehammer to try to break in and rescue at least three people who died in a house fire in Fermanagh.
Catherine Fee (27) said her father Tom owned the rented house on Molly Road near Derrylin and had been contacted by a friend this morning to alert them to the fire.
The student, who lives just a few minutes away, said: "She said there was a fire in the house and there was smoke coming from the roof.
"My dad got up and went down to check. He tried to get into the house. They (her father and a neighbour) smashed the windows in trying to get into the house."
She added: "It's just so tragic, it's an awful shock."
A man aged 27 is being questioned on suspicion of murder after he was detained at the scene and transferred to hospital for treatment, police said.
Sinn Féin MP Michelle Gildernew said local people had attempted to smash a window but were unable to get in and save the family as the property was consumed by the blaze.
She added: "As somebody who goes to a house in good faith to try and help people and people die, that is just, it's horrendous. It's hard to take."
The whitewashed rural bungalow in Derrylin, near the border, was destroyed in the blaze and the roof collapsed, leaving a shell surrounded by farm buildings and machinery.
The victims had only moved to the area recently, a local priest said, and were members of one family.
They had previously lived in the Republic and were originally from England.
Fire engines and police cars were coming and going from the scene for most of the day.
PSNI Superintendent Jane Humphries, commander for Fermanagh and Omagh district, appealed for witnesses.
"We believe the fire began in the early hours of the morning and we are particularly keen to speak to anyone who was in or travelling through the Derrylin area between midnight and 10 past seven this morning."
Ms Gildernew said neighbours who had tried to help were "badly shaken".
"I understand they used a sledge and tried to break a window to gain access but weren't able to do that."
Emergency services remain at the scene as they investigate the blaze, which the PSNI said they believe was started deliberately pic.twitter.com/dX8qWKwKpr
— Aine Fox (@aine_fox) February 27, 2018
The victims were members of the same family, DUP leader Arlene Foster said.
Northern Ireland Fire & Rescue Service (NIFRS) said officers took an emergency call about the fire at 7.14am on Tuesday.
The blaze occurred in a rural lane near the scenic Doon Road. It was "well-developed" when firefighters arrived in three appliances from Lisnaskea and Enniskillen, the service added.
Neighbours made desperate attempts using a sledgehammer to try to save those in the house, MP @gildernewm told @PA pic.twitter.com/rc2NGVfrPI — Aine Fox (@aine_fox) February 27, 2018
Police tape sealed off the entrance to Molly Road. It is the only house on the lane, surrounded by farm buildings and fields.
The fire was extinguished and police and fire officers are determining if anyone else was involved in the incident.
A spokeswoman for the fire service said: "The thoughts of NIFRS are with the family, friends and local community at this time."
Mrs Foster added it was devastating news for the local community and there was widespread shock in the area.
"It is important that the cause of the fire is established but my thoughts and prayers are with all those in the local area, friends and the wider family circle as they struggle to come to terms with this terrible tragedy."
