FIRST,,,,

for your losses.
You have to understand one thing. The raccoons are not mean.. BUT like all animals, do need to eat.
They may make a visit to see if there is a possibility, and then keep going further.
Like you stated,, You secured your run. "Fort Knoxed"
Reality with raccoons,, is they hunt usually after dark. Now that the days are long, I have seen them out before nightfall. Early evening.
Just do your best to keep coop, and run secure. Also do be aware they can climb, and enter from above. I don't know how your run is protected.
Fox, another predator, operates day and night.
A pack of 4,,, sounds like a mama racoon, and 3 cubs. Eventually the pack will break up and seek their own territory.
WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,