I agree that event is concerning.

But it's also a small sample size and there could be many reasons why, in that group, the numbers came out the way they did, including natural clustering.

That would also explain the OPs anecdote as it's very possible an individual hospital is seeing more hospitalizations among the vaccinated just due to the vagaries of statistics. That's why large sample sizes and careful analysis are so important when coming to these conclusions.

But we have substantially more data from Canada and the UK and so far that data shows that the vaccines are effective versus Delta.