User blog comment:Miskos3/Fairy Tail Chapter 334: Sin and Sacrifice, Review/@comment-203.215.121.20-20130608014243/@comment-7418318-20130608082754

Levy was cutting her letter off when she couldn't take it anymore, so most likely the list would have continued for quite some time.

I don't know about f-Lucy's timeline, but in f-Rogue's timeline he said that 90% of Mankind were wiped out, just by Acnalogia alone! Now imagine what 10.000 Dragons would do. Probably the same, but in much shorter time would be my guess.