A driver was lucky to escape with only moderate injuries after a piece of wood hit an SUV in Christchurch on Friday.
The crash happened about 1.35pm along Main South Rd, Islington.
A police officer at the scene said the trailer, which was full of timber, disconnected from the vehicle.
It then went onto the wrong side of the road and a piece of timber came off the trailer and hit the SUV's windscreen.
The officer said the driver had dislocated their thumb - but they were lucky that was all.
St John ambulance spokesman Gerard Campbell said the patient was taken to Christchurch Hospital by ambulance.
A Fire and Emergency NZ spokesman said the injured person did not have to be cut from the vehicle.