Use of と in 亡くなった人と亡くなっていたことがわかった人

Question

I'm reading this article about a peace ceremony held in Nagasaki.

There is a sentence that uses a と, but I do not understand the meaning entirely. I believe the と is being used as an "and" but I don't know why or how. I have only seen と used as an "and" when its is between two nouns like

猫と犬

Cat and dog

If I am correct is it because the と is between two relative clauses?

Sentence: 去年からの１年に亡くなった人と亡くなっていたことがわかった人は３５１１人です。

My Translation: Since last year, people that have died in the year and people who understood the event that were dying are 3511.

Answer 1

Here the と is between two noun phrases. (The noun phrases are 亡くなった人 and 亡くなっていたことがわかった人.) Noun phrases can behave exactly like nouns, so in 猫と犬 you can replace the nouns 猫 and 犬 by more complicated noun phrases.

Indeed, both noun phrases consist of a noun (in both cases 人) modified by a sentence ending in a verb and this structure is often translated using a relative clause in English.

You only asked about the grammar of と, but let me also remark that your translation is too literal. For

亡くなった人は5人です。

I think it would be more natural to say

Five people died.

rather than

People who died are five (persons).