Photo: CM Lisboa
The building was undergoing renovation work at the time its interior façade gave way.
The fatal victims are two a Portuguese men; labourers who were working on the renovations at the time of the collapse.
A third employee, who was also working on the building, managed to escape in time and survived the incident.
Traffic was cut off around the area and a security perimeter set up while search and rescue operations took place with sniffer dogs.
The Work Inspection authority is now to establish the cause of the accident.