These things happen 

usually used with the words "I suppose...." before "these things happen." A phrase which is similar to shit happens and it is what it is. This expression, though, implies that the action that caused the saying of the phrase was so hopelessly terrible to the speaker, that him/her don't have anything to say, and use it as a means of justifying the terrible event.

1: Damn, I just lost my kids in a court case.

2. These things happen.

These things happen by Alfons Richter April 3, 2008

These things happen 

A consolation offered to someone who has just experienced something shameful or embarrassing. This may be particular to Northern Ireland but I cannot confirm.

Seems common place amongst traditional working class families, a type of "stiff upper lip" attitude.

"Awhk Billy, you've never been done for drink driving before."
"Awh a'know but I'm just so embarrassed about it."
"Louk', these things happen."

These things happen by WE CANT GO ON TOGETHER WITH SU May 27, 2013

The second worst thing that happened to these orphans

Technoblade

"I was The second worst thing that happened to these orphans"

The second worst thing that happened to these orphans by Icaruswastaken June 15, 2022