2 nestlings and parent. No vocalizations that I could hear. It looks like the chick on the right got the prey item in the beak, and the left one got something regurgitated.
Here is the observation for the prey item:
https://www.inaturalist.org/observations/214236680
Tough to get a photo of a snake in murky water! About 1.5' long. Was swimming, then went dead still in the water, with only snout poking up for over 5 minutes. So this is the best shot I could get.