Is it possible they got into the water? If nothing else, it may have kept them from overheating to death. They'll dry and be fine if you have the brooder at 85-90 and let them find a comfy spot- they will self-regulate if you have the light in one corner and allow them to move to the spot of the correct temp for each chick.
In my brooder, I have an area of 100 degrees that is one corner (like a square foot) and then they come and go from that area the way they would from the Mama- warm up, go away. Come back, warm up again.
It's 6'x2 1/2' so the heat is at one end (very extreme) and they roam the length. Sometimes they get in the waterer. They'll just hang out nearer the light until they dry. The whole brooder should NOT be the temp one assumes the birds require.
I use an oven rack over the brooder when they get out.