A 19-year-old man was seriously injured in a fall on a Mellieħa construction site in the early hours of Saturday morning.
The police said in a statement the accident happened at around 2.30am on Triq ir-Ramla.
Two Austrian men - aged 18 and 19 - climbed on the roof of a building with the latter falling into a shaft that is five storeys high.
He was given first aid on site by a medical team and members of the Civil Protection Department.
Magisterial and police investigations are ongoing.