Sorry for your loss (and thankful I live in relatively predator free NZ)
Last year we had a rat problem, thanks to a neighbour who insists on putting egg shells and food in his compost, and I lost 3 ducklings in one night to rats, after seeing them around for a while, and spending time trappin them etc, but not wanting to use bait due to it being cruel and they hadn't touched any of the ducks or ducklings,so I got blaise about the risk
Well after I found one of the ducklings,it was WAR. Bait, plus I went out and brought an air pistol and dispatched several of them to rat heaven the same day. Funny how your perspective changes when you realise it's them or your babies.... I now have no qualms in shooting any rat or mouse I see, and while I still don't like the way bait works, I consistently use it, as it's the only way (short of shooting the real problem, my neighbour who still puts food out for the local rodent population) to control them, and it's a either that, or lose my ducks, and I am not going to lose my ducks...
I also now keep all ducklings in cages with very small diameter wire around the entire run and where the run sides meet the ground I either put cement in, or put the wire out across the ground for 6-8 inches. Unfortunately with rats, the only way I have found to sucessfully control them is bait.
Not sure what the best option is with raccoons, but maybe sitting outside the coop with a gun? That's how I spent the nights following the duckling deaths... Drank a lot of coffee at work that week!