James Mueller, 76, and Donna Mueller, 75, of Janesville, Wisconsin, died of their injuries Thursday evening, a Metropolitan Police Department spokesman confirmed to the television station CNN. The condition of the other two injured was not immediately clear after the incident.

Two men and two women were hospitalized Thursday evening with critical and life-threatening injuries after an incident in Lafayette Park, the Columbia County Emergency Medical Services Department said.

According to the website, the police officers who witnessed the attack started Axios provide immediate assistance to those people.

A strong thunderstorm hit the DC area around 7pm local time on Thursday. The National Weather Service has issued a severe thunderstorm warning for the area. According to witnesses, there were six strong flashes near Blo dom at 18:49.

Lightning strikes kill an average of 20 people in the US and injure many others.