Eight individuals incarcerated at the Grafton Reintegration Center in Ohio were hospitalized Tuesday after a lightning strike, authorities said. The incident was declared a mass casualty event.

Officials stated the individuals were struck as they were moving between buildings following a meal. All eight were transported to local hospitals with injuries that were described as non-life-threatening, though some patients were critically hurt. Ambulances from Lorain, Medina, and Cuyahoga counties responded to the scene, and University Hospitals in Elyria and Westlake were prepared to receive patients.

The lightning strike occurred as Ohio was experiencing severe weather, including powerful storms that caused widespread flooding. One person died in Roseville due to a medical emergency that first responders could not reach because of floodwaters. Ohio Governor Mike DeWine signed an emergency declaration for Perry and Muskingum counties, confirming the fatality.

The National Weather Service had issued a flood watch for the Grafton area beginning at 11 a.m. Tuesday and expected it to last until 8 a.m. Wednesday. The NWS advises seeking shelter immediately after hearing thunder and remaining indoors for at least 30 minutes after the last thunderclap. While indoors, people are warned to stay away from electrical equipment and corded phones. If caught outside, individuals are advised to move to lower ground, avoid isolated trees, get out of bodies of water, and stay away from conductive objects.