A 54-year-old man is in critical condition after falling off a ladder, the police said.
The incident happened yesterday at about 7.30pm when the man, who is from Floriana, was working at stables in Naxxar.
Magistrate Francesco Depasquale is leading an inquiry.
WOMAN SERIOUSLY HURT IN TRAFFIC ACCIDENT
A 40-year-old woman was also critically injured late yesterday in a crash involving two cars in Mdina Road, Zebbug.
The woman, from Sta Lucija, was a passenger in a Fiat Uno which was involved in collision with a Ford Focus.
The Punto was being driven by a 23-year-old woman from Paola, while a 20-year-old man from Mosta was driving the Focus.
The Punto's driver and another passenger - a 46-year-old woman from Xghajra - were also hospitalised.
The Focus driver and his passengers - a 17-year-old woman from Mosta and a 22-year-old man from Mosta, were unhurt.