A workman was rushed to hospital after an incident at a construction site in San Ġwann on Thursday morning.
Witnesses said the victim, a 45-year-old Liberian national, was heard calling out for help, as he fell down the height of around three storeys.
The incident happened in Sqaq Tomna just before 8am.
His condition was described as "grievous".
In another incident, firemen were called to control a fire which broke out in a warehouse in Marsa, close to the A3 towers.
Police are investigating both incidents.