The accident happened in Arturo Mercieca Street.
A young worker was rushed to hospital following a construction accident in Sliema on Saturday morning.
Police said the 20-year-old worker was demolishing a roof with a jackhammer in Arturo Mercieca Street around 10.30am when the roof caved in. He is believed to have fallen a height of two storeys.
The victim, a resident of San Ġwann, was rushed to hospital in an ambulance. His condition is not yet known.
Police are investigating.