Well would you believe that it is not uncommon for one or two people to die on a cruise? I went on a 10 day cruise a few years ago and three people died on it. They chucked 'em in the fridge and carried on the trip like it was normal.
So if you're floating around with 4690+ people, naïvely, about 39 people should die on it every year, or one every 9.28 days.
On a 10-day cruise of that size, somebody is going to die. I bet once you control for the unusually high average age of the passengers and maybe other factors (how many drunken idiots fall over the side and drown every year?), 3 people in 10 days would be pretty normal.
[1]https://www.cia.gov/library/publications/the-world-factbook/...