Screams were heard by neighbours after a woman was killed and a two-year-old girl was left seriously injured in Ashford.
Police were called to Imtech house - a former office block being used as temporary housing for families - after receiving a report of concerns over safety at the address.
Both the woman, aged in her 20s, and toddler were found at the block on Woodthorpe Road at 1.15pm on Thursday with serious injuries.
Despite treatment from paramedics, the woman died at the scene, while the child was rushed to hospital.
Surrey Police launched a murder investigation and arrested a man in his 30s on suspicion of murder and attempted murder.
The force said the victims and suspect are known to each other and there is not believed to be a wider risk to the community.
A neighbour to the former office block told The Independent: “There were so many police around last night - it’s so shocking. We’ve heard about it.
“The young girl has died and her baby was injured. It was inside Imtech house, a former office block that has been converted into little one-bedroom units.“
Neighbours said they heard “screaming and shouting” before police arrived and the scene turned into “chaos”.
One said: “It was chaos. We heard screaming and shouting. It was definitely a woman. Ashford is a peaceful area but that block is problematic. It’s a great shame.”
Another said: “I saw a child being taken out and a man being arrested. There was a very large police presence and an air ambulance.”
One resident claimed his friend lived in the housing block and he was shut out of his flat for three hours while police attended.
He added: “There was an air ambulance that landed at a field in the nearby primary school. There are a lot of really lovely people living in there, but they’re vulnerable.”
Before the incident, Ashford Conservatives launched a petition complaining about anti-social behaviour surrounding Imtech house, which is being used as temporary housing for families from the neighbouring borough of Spelthorne.
Leader of Spelthorne Borough Council Joanne Sexton said: “I am truly shocked at this devastating news.
“I recognise this is a very worrying time for residents but please be assured that there is no wider risk to the community, however I do urge anyone who can assist with the investigation to get in touch with the police.
“As a matter of course, the council will be holding a meeting to review this incident and offer our ongoing support to the wider community.
“My thoughts are with everyone affected during this sad time.”
Senior investigating officer detective chief inspector Kimball Edey said: “This investigation is in its early stages and a team of specialist officers are working around the clock to gather as much information as possible.
“Our thoughts are with the family and friends of the victims at this unbelievably difficult time.”
Anyone with information is asked to contact police on 101, quoting PR/45250005886. Alternatively, the independent charity Crimestoppers can be contacted anonymously on 0800 555 111.
