Five people including a nine-week-old baby girl and two other children aged nine and seven have died in a house fire.
Shabbina Begum, 54, and her 20-year-old daughter Anum Parwaiz Kayani, are also believed to have died in the blaze that broke out in Wake Road, Sharrow, Sheffield.
A nine-week-old baby girl was among those who had died, as well as nine-year-old Adhyan Parwaiz Kayani and seven-year-old Amaan Parwaiz Kayani.
Father Nazim Parwaiz Kayani, with his two sons Amaan, 7, and Adhyan, 9, who were killed in the fire
Begum is understood to have managed to get out of the house but died when she went back in to try to rescue her grandchildren.
Begum's cousin Ishfaq Hussain Kayani said the children's father, Nazim Parvaiz, was out working when the fire broke out but their mother, Razia Nazim Kayani, survived the blaze.
He said she is being comforted by family members.
People living in the area said up to 300 people came out in the street to try to offer help as the emergency services arrived.
Some neighbours reported hearing screams and wailing from the area when they were woken in the early hours.
"It's just a huge tragedy. Words cannot describe how sad this is," Hussain Kayani said. "It's a tragedy beyond description."
He said of Parvaiz: "She was, to my children, like a mother, like an aunt. The whole community is in huge shock.
"As soon as the news broke just after midnight, we came round. I've been with the family.
"It's so sad. A couple of hours ago the whole family was leading their normal life - quite prosperous, happy.
"Just in a matter of minutes the whole family has been destroyed. The whole family has gone.
"You can well imagine what the children's parents are going through. I don't have the words to describe how the family is feeling, other than shell-shocked, devastated.
"We are a close-knit family, there are enough people around to support the family."
He added: "They were such a lovely family, highly respected. Quite an industrious family who had everything going. This tragedy has struck and we have to try our level best to pull through this."
South Yorkshire Fire and Rescue said the fire began shortly after midnight on the residential street, which is lined with cars on both sides.
Emotional residents on Wake Road, Sheffield where five people have died in a house fire
A fire brigade spokesman said: "An investigation has commenced, involving police and fire officers, to establish the cause of the fire."
Four fire engines were called to the scene and an aerial ladder was used to tackle the blaze.
Police and ambulance services also went to the house after receiving emergency calls.
Police, who cordoned off the road, said the damaged building was a terrace house.
A South Yorkshire Police spokesman said: "At this stage we are not able to confirm where in the house the fire broke out or if anyone else was injured."
Police officers and firefighters remained at the scene, he said.
A spokesman for South Yorkshire Fire and Rescue said details about the fire would become clearer later today.
He said: "Our investigators are arriving here at 9am, so we will know more later on this morning."