A Dundee City Council worker was rushed to hospital after a mini-digger toppled down an embankment.
Police and paramedics were called to Kinghorne Road following the incident.
A bystander said a man had been inside the vehicle when it toppled on a slope in the grounds of the West Law allotments.
It is understood work had been taking place on the premises to erect a new fence around the allotment perimeter.
A city council spokesman confirmed an investigation had been launched.
It is believed the man sustained a head injury after falling out of the digger.
Council workers were at the scene at around 4pm yesterday, using a larger machine to try to stabilise the mini-digger on the slope.
A dog walker who witnessed the incident said the digger was close to toppling on to a public footpath.
She said: “I live very close by and I was out walking my dog.
“I saw the workers trying to shore up the vehicle.
“It could have been worse given how close the digger was to coming down on to a public footpath.”
Another eyewitness said: “I heard a commotion and saw the digger was couped over.
“There was one police vehicle at the scene just after 3pm.
“The paramedics were positioned slightly further down the road.
“We heard the man had split his head open after falling out of the vehicle.
“It’s very lucky the vehicle didn’t come down with the guy still inside.
“I understand he was carrying out improvements on fencing around the allotments.”
A spokeswoman for the Scottish Ambulance Service said: “We received a call at 2.42pm to attend an incident at Kinghorne Road.
“An ambulance was dispatched to the scene and one male patient was taken to Ninewells Hospital.”
The council spokesman said: “An investigation is now ongoing into the circumstances of an accident which happened during fencing work at allotments near the Law.
“An ambulance was called to the scene and council officers have been in contact with the injured employee’s family.
“It would not be appropriate to comment further at this time,” he said.