A family that was found dead in their home were about to go on holiday in Spain for the father's birthday, according to a neighbour.
Michal Wlodarczyk, 39, Monika Wlodarczyk, 35, Maja Wlodarczyk, 11, and Dawid Wlodarczyk, aged three, were all found dead after police forced entry to their home on Friday.
A tearful mother said her daughter – who was in year six with Maja at nearby Southville primary school - attended a sleepover party at the house on May 31.
She also said the family were planning to go to Mallorca soon to celebrate Mr Wlodarczyk's 40th birthday.
Maria Gouveia, 37, told PA news agency: “It’s tragic, her parents were really good people, hard workers, the mother was a cleaner in a hotel, I think the father was a builder.
"Maja was a lovely, beautiful girl, with a strong personality, but she had not been in school for a few days. People in her class were texting her, my daughter messaged her on Snapchat, it was not like her to go quiet.
"I think they were going to Mallorca for the dad’s 40th birthday very soon, that’s where I hoped they were when I heard about this. It’s shocking, the little boy was so sweet, he was going to start nursery in a few months, we are praying for them.”
Another mother, Naura Hooper, 46 – who attended the scene - said she used to take Maja out with her daughters. She said: “Maja was a nice girl, very intelligent and well-liked, the family were nice whenever I met them.”
Police are continuing to investigate what happened and it is being led by homicide detectives from the Specialist Crime Command.
Detective Chief Inspector Linda Bradley, who is leading the investigation, said: “I would like to assure the community that specialist detectives are working to establish the circumstances which led to this tragic incident and we will provide further updates as soon as appropriate. Our thoughts are with everyone who has been affected by what has happened.
“Our investigation is at an early stage, and the situation remains that we are not currently seeking anybody else in connection with the incident.
“We are however retaining an open mind, and I would ask anyone who feels they have pertinent information to contact us as soon as possible.”
Chief Superintendent Sean Wilson, local policing commander for west London, said: "I know the shock and distress that this terrible incident will cause among the community in Hounslow and beyond.
"I am also aware that this incident will be particularly upsetting for children, and I ask people to please be responsible about what they post on social media, including not naming or speculating as to the names of those who’ve died.
“There will be additional police officers in the area across the weekend, I urge anyone with information or concerns to speak with those officers.”
Enquiries continue and special post-mortem examinations will take place in due course.
Anyone with information that may assist the investigation is asked to call 101, quoting reference 5135/16Jun. Alternatively please provide information via the online form at: https://mipp.police.uk/operation/01MPS23V28-PO1.
