A construction worker fell one storey down a skylight in Senglea on Monday afternoon, the police said on Tuesday morning.
The 52-year-old was working on the roof of a site on Triq San Lawrenz when he fell at around 2pm.
An ambulance was called to the scene and took him from there to Mater Dei Hospital, where doctors found that he had been grievously hurt in the fall.
A police investigation is under way.