What would you do?

So just want to start off by acknowledging that everyone has their own parenting style and no judgement to others however, this personally didn’t sit well with me. I’m currently on vacation and was in the swim up bar pool- the sun is beaming and it’s pretty hot weather. We notice a baby crying her lungs out in black stroller at the side of the pool all alone. I’ve seen this baby before and knew that her parents were having a drink inside the pool by the bar area. I was about to go and tell them that their baby was crying but another woman beat me to it. They literally started laughing, raised their drinks, said “we know” and continued to do their own thing. This poor baby was literally screaming and they kept looking at her from the bar, laughing, dancing and enjoying their drink. The lifeguard seen what was happening and told the parents again that the baby was freaking out. The dad said to his wife “he’s saying the baby is crying” rolled his eyes, walked up to the stroller, waved, and then left her….again! They eventually took the baby out and into the pool I guess after noticing everyone around them starring. They kept her in the pool for about 10 minutes and then back in the stroller she went. I should mention the baby seemed to be under 1 I just don’t get. I understand you’re on vacation and you want time to yourselves to relax but come onnn! Leaving your baby in scorching hot weather in a black stroller… she must have been over heating. And then purposely not attending to her when you know damn well she screaming and crying? Bring a nanny or leave your baby home with a family member if your intentions are to leave your children in situations like that. Sorry, had to vent because this is still bothering me.