Tuesday’s Virginia earthquake triggered the shutdown of a nearby nuclear power plant and spurred declarations of “unusual events” at plants as far away as Michigan, U.S. authorities reported.

Dominion Virginia Power said both reactors at its North Anna plant, less than 20 miles from the epicenter of the magnitude-5.8 quake, shut down automatically after the first tremors.

Amanda Reidelbach, an emergency management spokeswoman for Louisa County, said the plant vented steam, but there was no release of radioactive material.