Hi,
A student learning English as a second language used this sentence construction:
It was lucky that we could see you.
to make this sentence:
It was happy that the man did not die.
Is that second sentence right or wrong. And, if it is wrong, why does this sentence work:
It was a happy event that the man did not die.
'It was lucky that . . .' is an idiomatic phrase. We say this because we like saying it. 'It was happy that . . ' is not an idiomatic phrase.
'It was a happy event' is just standard, common grammar.
Best wishes, Clive