Police believe they know what happened to missing dog walker Nicola Bulley

Nicola went missing a week ago today.

Police on Friday revealed that the "main hypothesis" in the disappearance of Nicola Bulley is that she fell into the River Wyre in the UK. The mortgage broker was last seen walking her dog along the River Wyre, Lancashire, around 9.10am Friday, after dropping her two daughters off at school in St Michaels on Wyre. Superintendent Sally Riley said offices believe the 45-year-old mother-of-two fell into the River Wyre, "accidentally". Riley adds: "Our main working hypothesis therefore is Nicola has sadly fallen into the river, that there is no third party or criminal involvement and this is not suspicious. "This is particularly important because speculation otherwise can be really distressing for the family and for Nicola's children." When questioned by reporters, Riley suggested that a possible "issue" with Nicola's dog may have led her to the water's edge. The dog, a cocker spaniel called Willow, was off-lead at the time. Riley said: "It is possible that there may have been an issue with the dog that led her to the water's edge. "We assume the dog didn't enter the river but we don't know why Nicola may have if she did." However, Riley made clear that this is speculation, but pointed out that there is "quite a steep drop to the river" from the area where Nicola's phone was located. "Therefore, whilst I don't want to speculate as to what may have happened, it is our working hypothesis that she's entered the water accidentally," Riley said. The underwater search, Riley said, has been "very thorough". Earlier today it was revealed that Nicola sent a final text message, at 8.57am, arranging a playdate with a friend whose mortgage she had recently signed off. One unnamed resident suggested the text was further evidence Nicola had no intention of voluntarily disappearing: "You wouldn't have done that if you were going to get up and go missing." Nicola's partner, Paul Ansell, spoke out on Friday saying his "whole focus is the two girls, staying as strong as I can for them". https://twitter.com/SkyNews/status/1621466024427020288   On Thursday, Nicola's sister, Louise Cunningham made a heartfelt plea, saying she needed to "get my sister back". "Something has got to have been missed. Somebody must know something. People don't just vanish into thin air. "There has got to be somebody who knows something and all we are asking is, no matter how small or big, if there is anything you remember that doesn't seem right, then please reach out to the police. Get in touch and get my sister back." Cunningham said her family felt they were "stuck in a nightmare". Nicola's dad, Ernie Bulley added: "There are two young children there waiting for their mummy to come back and we want her back obviously also, but if Nicola is out there, if she's watching this, then all we'd like to say is: 'Come home, contact the police, contact ourselves and we just want you back.' "And they know that mummy's missing but they know that she's going to be coming home and everyone is looking for her, so it's only a matter of time, that they're thinking in their minds that she's going to walk through that door."