My penny worth. I suspect leatherjackets and chafers....they did the damage in autumn.
However, I also feel Dove is right .....too wet and the worms are coming to the surface. They aren't the reason for bare or dead areas. You would also see worm casts.
When it dries out a little I would spike and rake the "lawn" ......in order to create a fine tilth for re seeding in early April. A scattering of fertiliser after spiking and raking would not be a bad thing either.
For next year I would consider nematodes to control leatherjackets and chafers in late summer