Police advised that motorists avoid the area surrounding Hagden Road in Watford this morning as emergency services respond to an injury on a building site.
Police were called to the scene at around 10. 18am, with the ambulance and fire services also on the scene.
Due to the work being carried out by emergency services, people were told to stay away from the road.
A spokesperson for Hertfordshire Fire & Rescue added: “Hertfordshire Fire and Rescue Service was called at 10:25am this morning to reports of a wall collapse on a building site in Hagden Lane, Watford.
“A f ire engine from Watford fire station and the rescue unit from St Albans were sent to the scene, where firefighters worked to make the scene safe while the ambulance service treated an injured person.”