It happened today (Tuesday 15th July) at around 3pm at the junction of Watson Road and Ryton Street.
Three ambulances, three fire engines and specialist rescue services from Tuxford were in attendance.
Shocked residents and shopkeepers who had gathered at the scene looked on as the roof was severed off the Fiat by firefighters and an unconscious man lifted out.
Another man, who also appeared unconscious, was carried off in a stretcher by the ambulance crew.
A police cordon is currently in place, the cars have been towed away and emergency services have now left the scene.
Keep checking our website for updates.