Residents have expressed their shock after arsonists poured a chemical through the front door of a family home and set it alight.
Police said an "accelerant" was poured through the letterbox of a home in Montford Drive, Burngreave, while the occupants were asleep upstairs.
Neighbours said a woman aged in her 20s lives at the property with her two sons and a daughter. All managed to escape the blaze unharmed.
Residents told of their "disgust" today that someone could do such a thing.
One man, who has lived in the street for more than two decades but did not want to be named, said: "It is shocking that someone would do this, absolutely disgusting.
"The people inside, which included three children, could have died. The first thing I saw was the police car outside the day after. In all my time here this is the first real trouble we have had. It's a quiet street generally."
He added he has since seen a removal van outside and believes the young family may have moved out.
A woman who also lives on the road added: "I know the woman to say 'hello' to but I haven't seen her since the fire. It is horrible that this has happened on our road."
A 21-year-old man arrested on suspicion of arson has been released by police under investigation as enquiries continue.
The incident happened on Thursday, May 25, at about 12.40am.
A South Yorkshire Police spokeswoman said: "Officers are asking anyone who saw or heard anything suspicious in the area in the early hours of that morning to get in touch via 101.
"If you have any information, please call 101 quoting incident number 36 of 25 May 2017 or call Crimestoppers anonymously on 0800 555111."