This is the terrifying moment passengers fall from a tourist boat after it was struck by a towering cruise ship on a busy canal in Venice – injuring four tourists. The collision, which saw the luxury MSC Opera cruise liner crash into the small River Countess and the San Basilio dock, took place at about 8.30am Sunday on the Giudecca Canal – one of the major canals in the ancient city. Horrifying images showed the hulking cruise ship sounding its horn as petrified tourists attempted to move out of its way. Passengers can be seen leaping from the river boat which was smashed in the head-on collision – leaving it severely damaged Medical authorities say four female tourists – an American, a New Zealander and two Australians between the ages of 67 and 72 – were injured falling or trying to run away when the cruise ship rammed into the tourist boat. MSC Cruises said the 2,679-passengers onboard the 177-ft high and 902-ft long long liner, which dwarfed the Venice skyline, were approaching the terminal when the ship hit the dock after a technical problem. The collision comes days after seven people were killed and 21 remain missing after the Mermaid, a sightseeing boat, capsized on the River Danube in Budapest, Hungary.