The fire service said it found no working smoke alarms in a house where a fire killed two young boys.
Three-year-old Logan Taylor and two-year-old Jake Casey could not be saved after being rushed to hospital from the blaze at a property in Huddersfield.
Their mother and an older brother escaped.
Tributes have been left for the two young boys who died in a house fire in Yorkshire.
They've been named as Jake and Logan on some of the floral tributes.
The brothers aged two and three were rushed to Huddersfield Royal Infirmary but could not be saved.
Their mother and another brother were able to escape the semi-detached home in Alder Street, Huddersfield, before the crews arrived.
The death of two young boys in a Huddersfield house fire has left the community in shock.
Local Labour councillor Amanda Pinnock described the incident as a "tragedy".
"Because of the area, everybody knows everybody," she said. "They will be shocked by what has happened."
It is believed the house did not have a working smoke alarm.
Chris Kirby, group manager at West Yorkshire Fire and Rescue Service, said the two boys have suffered "significant smoke inhalation".
He added that many of the fire crews had "tears in their eyes" after the children were pulled from the building.
A house fire which killed two young boys in Huddersfield is not believed to be suspicious, police have said.
Emergency services were called to the property in Alder Street shortly after 2pm on Saturday.
A West Yorkshire Police spokesman said: "A woman and a child, who had been in the property, had made their own way out prior to the arrival of the emergency services with fire crews removing two other children from the address. Both of these children were pronounced deceased a short time later.
"The children have yet to be formally identified but are believed to be two boys. Their next of kin have been made aware."
"Enquiries continue in to the cause of the fire, but at this time it is not believed to be of suspicious origin."
Two young boys have died following a house fire in Yorkshire.
Fire crews were called to the property in the Fartown area of Huddersfield shortly after 2pm on Saturday.
A woman and a six-year-old child had managed to get out of the house but told emergency services that two young children were still inside in an upstairs bedroom.
Firefighters found the two boys inside the house, believed to be aged two and three, and they were taken to hospital, but died a short time later.
"This is a tragic incident where two young lives have been lost," a West Yorkshire Fire and Rescue Service spokesman.
The fire service is still investigating the cause of the blaze.
Police are searching for a man who left his partially severed diamond-studded ear on the pavement after it was bitten off in a fight.
West Yorkshire Police believe the man did not seek medical treatment after the incident in Huddersfield at about 9.20pm last night and are urging him to come forward.
A photograph of the ear, complete with the diamond stud earring, has been posted on Twitter but the victim has not yet been traced.
Two men, aged 37 and 45, have been arrested on suspicion of wounding and are currently in police custody.
A force spokesman said: "The male who we believe was injured in this incident has still not been traced and has not contacted police."
Anyone with information is urged to contact police on 101 or Crimestoppers anonymously on 0800 555111.
Forensic officers have arrived at a house in Huddersfield where a woman has been killed and four children injured. A 37-year-old woman was found with stab wounds at a home in Reinwood Road. She was taken to hospital but later died. Four children including a six-month-old baby were also injured.
A man in his 30s has been arrested in connection with the incident.
A murder inquiry has been launched after a woman's body was found in Huddersfield yesterday. Officers were called to Reinwood Road in the Marsh area of the town last night after reports of an ongoing domestic incident. A 37-year-old woman was found at the house suffering from a serious stab injury.
She was taken to hospital but later died. A nine-year-old boy was also found outside the house. He was taken to hospital suffering a stab wound to his arm. An 11-year-old boy, was also found inside the house. He had suffered stab wounds. Both are in hospital.
A six-year-old boy and a six-month-old baby girl were treated for minor injuries.
"A 39-year-old man was detained at the scene and is being treated in hospital for serious injuries. We are not looking for anyone else in connection with this incident,"
Senior Investigating Officer, Detective Chief Inspector Ady Taylor
Reinwood Road in the Marsh area of Huddersfield has been closed in both directions due to an on-going police incident. The road between Adelphi Road and New Hey Road/Acre Street is expected to be closed until later this morning.
The man responsible for the deaths of eight members of the same family in an arson attack has been recaptured in "a confused state" after he went on the run from prison, according to police.
Shakiel Shazad, 33, was picked up by officers from Staffordshire Police on a road between Lichfield and Rugeley yesterday afternoon before he was admitted to hospital.
He was released on a work licence yesterday but failed to return to Category D Sudbury Prison.
Shazad was sentenced to 18 years in jail in 2003 after he was found guilty of manslaughter following the blaze in Huddersfield, West Yorkshire.