Has the sky fallen?
No, it’s Siberian Squill (Scilla siberica), a European lawn weed that has naturalized in the lawns of large older historic homes in near northwest neighborhood in Elgin.
An abandoned house in my neighborhood last spring, contained not only Squills. but daffodils and Penn Sedge, as well.
Two miniature, cobalt blue lilies dangle from the top of 4-6” stems, surrounded by stiff green leaves. It multiplies quickly by seed; as lawn grass starts to grow, the plant conveniently goes dormant. Since the lawn is non-native, I don’t care if non-native plants grow within it; they can, however, become invasive in a wild flower garden.