As a publicity stunt, the ad agency M&C SAATCHI created the distinct impression that a submarine had accidentally surfaced through a street in Milan, Italy. The sudden and destructive appearance of L1F3 was a promotion for Europ Assistance IT, an insurance company.
The lesson appears to be that you need extra insurance just in case this happens on your street.
The agency went to great lengths to make this an almost convincing fake news story, including appearances by rescue workers, videos of the event taking place and interviews with the sailors. The captain, if I follow him correctly, claims that he was briefly distracted while driving.