Oh!
I just saw this. I'm so sorry.
Raccoons can go over fences and squeeze through amazingly small spaces. They often just eat a part. A hot wire would help with that, but not if it was a hawk. Was this a daytime or nighttime attack? Hawks are most active at dawn and dusk, but can hunt anytime. Perhaps you can confine them to a covered run while you are gone and just let them out to their pond when you are there with them.
So sorry for your losses. I know how special your ducks are to you.

Raccoons can go over fences and squeeze through amazingly small spaces. They often just eat a part. A hot wire would help with that, but not if it was a hawk. Was this a daytime or nighttime attack? Hawks are most active at dawn and dusk, but can hunt anytime. Perhaps you can confine them to a covered run while you are gone and just let them out to their pond when you are there with them.
So sorry for your losses. I know how special your ducks are to you.
