Severe storms swept across the Midwest on Tuesday, unleashing tornadoes, heavy rain and flash flooding that knocked out power to hundreds of thousands of customers. First responders and utility crews worked overnight into Wednesday clearing roads of trees and wires brought down by the system.

A 4-year-old boy was killed when a tree fell on a home in Geneva, Indiana, during Tuesday’s storms, the Jennings County Sheriff’s Office said.

In Ohio, Gov. Mike DeWine said a resident of Roseville died during a health emergency when first responders, faced with flooded roads, couldn’t reach them.

Officials in Portage, Indiana, were investigating whether the severe weather played a role in a reported house explosion that killed a person.

Lightning struck a prison complex southwest of Cleveland on Tuesday, injuring 16 incarcerated people who were hospitalized, according to the Ohio Department of Corrections. Their conditions weren’t immediately known.

Utility and emergency crews remained at work Wednesday, continuing to clear downed trees and wires as residents across the affected region dealt with the aftermath of the outages.