Becky mine was more devastating than paint and top soil. Our city mandated sewer installed. My son dug out a garden for me 20+ years ago. He dug down 2 ft and sifted all the rocks out of the dirt, placed it back in and we amended to get it perfect. My garden area is 15 ft x 30 ft. For years we had huge harvests out of this desert land. One year I counted over 3000 tomatoes off of 36 plants. Every crop you can imagine other than corn.
The sewer project required that our existing septic tank be crushed so a homeowner couldn't hook back up to it on their own. Most new houses have a septic in the front yard. Guess where my septic was?? Yep, right under my garden. They had to dig up the garden to smash the tank. I BEGGED them to PLEASE take out the first couple feet of soil and put it in one pile, then dig out the rest and put it in another pile. Crush my tank then put the rocky soil back in and top with my good soil. Did they listen? NOOOOOO! They took a bobcat and dug like the dickens and piled all the soil together and dumped it all back in the garden.
My pH was completely off, I had giant boulders in my planting beds. I would try to plant and the seedlings would die just after sprouting. My roto-tiller couldn't even make it through the soil without taking out a limb from the huge rocks. I was devastated. My heart and spirit for gardening completely broken. It has taken me about 6 years to even plant a seed. I have bought potted herbs for my little side garden and have had success.
I had a similar situation as yours with seedlings being eaten I planted bok choy, chard, kale and spinach.. 2 rows each. I put floating row cover on them, started to see seedlings and a day or two later, NOTHING! the entire rows vanished! I am guessing a lizard of some sort cause who else could get under row cover? Certainly not birds or bunnies! I will forge on...