Prosecutor Enrico Cierci told reporters that a timer and a gas canister have been found in the rubble, which "makes us think that the explosion was deliberate." No motive was immediately clear, but Alessandria police superintendent Michele Morelli told Sky TG24 there was no indication of terrorist involvement.
Sky TG24 reported that the timer was remote-controlled, and that the owner of the farm building, which had been renovated and has been up for sale for two years, had been questioned. An adjacent farm building that was part of the complex was not damaged.
One of the dead firefighters was buried under rubble, the body only recovered after hours of digging. Italy's interior minister, Luciana Lamorgese, visited the site, amid an outpouring of sympathy for the families of the dead and injured from Italian officials and authorities. Lamorgese declined to comment on the investigation.