Thunderstorms developed across several Midwestern states, including in Indiana
Lightning struck an Ohio prison during severe weather in the state on Tuesday, injuring 16 inmates, one of which had to be airlifted to hospital.
The prisoners were outside during the storm, moving between buildings after an evening meal.
Nine of the inmates have since returned to the correctional institution, while seven remain in hospital, including one in serious condition, the Ohio Department of Rehabilitation and Correction said.
Severe weather and flash flooding has ravaged parts of the US Midwest in recent days, generating tornadoes, strong winds and causing widespread power outages.
No staff were injured in the strike, the Ohio Department of Rehabilitation and Correction said in a Wednesday morning update on social media.
The nature of injuries to the inmate who was airlifted from the scene has not been disclosed. BBC News has contacted the institution for comment.
The lightning strike hit amid severe weather conditions across the Midwest region. The National Weather Service (NWS) has issued flash flooding warnings across Ohio and Indiana, and confirmed that three tornadoes touched down in Chicago's south suburbs on Tuesday.
Footage from across the region shows homes with damaged roofs and trees that have been downed as a result of the storms.
At least three deaths have been confirmed, including that of a four-year-old boy whose family's mobile home in Indiana was struck by a tree.
An Indiana woman was killed in a home explosion during a period of powerful winds of more than 100 miles (160km) per hour, according to CBS news, the BBC's US partner.
First response efforts were delayed as a result of the road conditions, said police captain Rob Maynard. He said that although they believe the storm played a role in the woman's death, they are unable to draw final conclusions right now.
There were also several gas leaks as a result of the storm, which can be caused when large trees fall and disrupt underground infrastructure, Maynard added.
In Ohio, another individual died when first responders were unable to quickly reach them during a flooding emergency, said Ohio Governor Mike DeWine.
"This is a very dangerous weather situation," DeWine said on Tuesday, while warning people to keep an eye on the news and use "common sense".
