Firefighters joined police officers and paramedics at the scene of a single-vehicle collision.
A spokesperson for West Sussex Fire & Rescue Service said: “We were called at 3.18pm this afternoon to reports of a road traffic collision involving one vehicle on the A24 Findon Road near Findon Valley.
“Joint Fire Control mobilised two fire engines and a heavy rescue tender to the scene.
“The road is likely to remain closed for some time this afternoon, and drivers are urged to avoid the area.”
A spokesperson for the South East Coast Ambulance Service said: “Ambulance crews attended, assessed and treated two patients on scene before taking them to Worthing Hospital for further medical treatment.”
Photos taken at the scene showed a bus became stuck, when trying to turn around to avoid the road closure.
Whilst the incident was ongoing, an AA Traffic News report read: “Road closed and heavy traffic due to rolled over car on A24 Findon Road both ways between A280 Long Furlong (Findon Roundabout) and Cissbury Avenue.
“Severe delays of ten minutes on A24 Findon By-pass Southbound between Washington Bostal and A280 Long Furlong (Findon Roundabout). Average speed five mph.”
The road had reopened in both directions, as of 7.10pm.

1. A24 collision
Part of the A24 is closed in Findon – and drivers have been urged to ‘avoid the area’. Photo: Sussex News and Pictures

2. A24 collision
Part of the A24 is closed in Findon – and drivers have been urged to ‘avoid the area’. Photo: Sussex News and Pictures

3. A24 incident
Photos taken at the scene show a bus has become stuck, when trying to turn around to avoid the road closure. Photo: Sussex News and Pictures

4. A24 incident
Photos taken at the scene show a bus has become stuck, when trying to turn around to avoid the road closure. Photo: Sussex News and Pictures