A 43-year-old man was grievously injured on Wednesday while at work in Gudja.
The police said the man, an Ivory Coast national, was injured on Triq Bir Miftuħ at 5.45pm when the road roller he was driving overturned.
The man, who lives in Qormi, was rushed to hospital.
Police investigations are ongoing.
In a statement later, the Occupational Health and Safety Authority said it was investigating the accident.