A murder investigation has been launched after a 19-year-old man was stabbed in west London.
Tyler Donnelly's body was found by joggers in Hanworth Park, Feltham, shortly after 07:40 GMT, the Met Police said.
A crime scene is expected to remain in place for some days to come, the force said.
No arrests have been made and a post-mortem examination will conducted in due course.
Det Ch Insp Brian Howie, leading the investigation for the Met's Homicide Command, said: "Tyler left his home around 21:10 on Wednesday evening and rode his bike along Elmwood Avenue and at some stage entered the park.
"He never returned home.
"Tyler's family and friends are inconsolable after receiving the worst possible news imaginable - our thoughts are with them and they are being supported by specialist officers."
The detective appealed for any witnesses to come forward to help the force with its investigation.
Ch Supt Sean Wilson, who leads policing in Hounslow, said: "I know that this incident will be a shock for those living and working in the area and my officers will be conducting additional patrols to provide reassurance to the community."