A 42-year-old man was seriously injured at a construction site in San Lawrenz.
The police said in a statement that the incident happened at around 2.15pm on Triq Wied Merill.
It transpired that the Nigerian man hit a wall after jumping out of the way of machinery that fell close to him.
He was given first aid on site before being flown to Mater Dei Hospital.
A magisterial and police investigations are ongoing.