Seedling Death?

I planted my seedlings(two with tap roots and two that had just cracked) in rockwool cubes that had been dipped in pHed water and put the rockwool in my grow rocks and my net pots in the system. after a few days there was still no sprout. I took the net pots out of the water two days ago because it looked as if the rockwool was too wet. there still is no sprout. did I kill my seedlings?

gee guys don't all respond at once