Det Ch Insp Louise Metcalfe said: “To residents who we have not yet spoken to, I would urge you to please review any CCTV you have from 08:00 BST on Sunday 7 June right through to 19:00 and please get in touch through our dedicated public portal which has been set up for this incident.
“We’re working hard to build a full picture of the circumstances around it, and I’d like to thank those who have already come forward to provide their accounts of what happened.”
Ch Insp Terry Fisher, Brentwood district commander, added: “I’m acutely aware that this incident is likely to have a significant impact in our community, and I know the investigation team is doing everything possible to fully understand the circumstances and progress this appropriately.
“The loss of a child is every parent’s nightmare, and I would ask that this family’s privacy is fully respected at this time, both in person and online.”