A dozen people, including young children, were taken to hospital after a tour vehicle overturned and plunged into a river at a theme park.
Police said the incident happened at 1245 BST on Tuesday at the Diggerland complex in Langley Park, near Durham.
The all-terrain articulated vehicle was giving 18 passengers a tour of the site, when it slipped down a bank, landing on its side in a river.
None of the injuries are said to be life-threatening.
A spokesman for Durham Police said the victims, including a number of children, were taken to the University Hospital at North Durham.
He said the most seriously hurt were a six-year-old boy, who suffered a serious foot injury and a woman who suffered suspected broken ribs.
The Health and Safety Executive has begun an investigation into the incident.
Diggerland has three sites, in County Durham, Strood in Kent and Verbeer Manor at Cullompton, Devon.
All the parks feature rides and exhibits of mechanical digger vehicles.
The company's promotional literature claims children can drive or be given rides in different types of construction machinery.
The Durham Police spokesman added: "As part of its normal route the vehicle went down a steep hill, but at the bottom of the 20 metre hill it failed to negotiate
"It toppled over a drop of several feet into the River Browney, landing on its side in the shallow water.
"The driver escaped unhurt and all his passengers were wearing seatbelts, which ensured no-one received life threatening injuries.
"Most of the casualties are expected to be released home after treatment.
"Officers attended the scene, as did officials from the Health and Safety Executive."
No-one from the company was available for comment.