An 11-year-old boy was rescued by firefighters after becoming stuck up to his chest in mud in Leicestershire.
Luke Collinson was trapped for almost an hour after older children forced him to retrieve their football from mud flats at Thornton Reservoir.
They left him, but his screams for help were heard by a dog walker who called emergency services.
A team used inflatable rafts to free him. The fire service said dry weather had created hazardous conditions.
Luke, who lives in Thornton, said he began sinking into the mud that he had thought was dry ground.
"I reached out for a log but then the mud collapsed on my foot so then I couldn't get out and I fell backwards because I lost my balance", he said.
"It was up to my chest so then I was getting really scared and I was gradually going in as I tried to struggle.
"[The fire crew] saved my life so I'm really thankful for them being there."
Mark Speight from Leicestershire Fire and Rescue urged children and parents to be aware of the dangers of playing around the reservoir.
"It's extremely dangerous on here. Please, please stay away from the water. Even if the water's not there, the mud underneath will suck you down", he said.
Police have spoken to the other children involved.