Dead birds by the hundreds scattered over the Allentown-Bethlehem-Easton Airport told a tragic story of feathered migrators whose journey south was halted. Just what caused the deaths of the birds could only be surmised. Two theories were advanced by ornithologists. One was that birds were migrating in strange territory. The other is that they were caught in turbulant storms which might have pulled them to the ground in a downdraft. Among the birds were woodpeckers, starlings, and warblers.