Washington(CNN) Three people are dead and one is injured following a lightning strike across the street from the White House Thursday night.
James Mueller, 76, and Donna Mueller, 75, died from injuries following the lightning strike in Lafayette Park near the White House Thursday night, a DC Metropolitan Police spokesperson confirmed. The couple was visiting from Wisconsin. Friday afternoon, police said a 29-year-old man died from his injuries. His name is being withheld pending family notification.
The condition of the other person who was injured has not been released.
The victims were riding out the storm under a tree, a law enforcement source said. The thunderstorm hit the DC region around 7 p.m. ET.
"We are saddened by the tragic loss of life after the lightning strike in Lafayette Park," White House press secretary Karine Jean-Pierre said in a statement Friday. "Our hearts are with the families who lost loved ones, and we are praying for those still fighting for their lives."
The three people killed were the 10th, 11th and 12th killed by lightning so far this year in the United States, according to John Jensenius, an expert at the National Lightning Safety Council.
The US averages 16 lightning deaths per year through August 4 based on data for the past 10 years, Jensenius said Friday evening. He also noted that this week's fatalities were the first in Washington since May 17, 1991 when one was killed and 10 others injured when lightning struck a tree at a lacrosse game.
"This incident underscores the need for people to get to a safe place any time a thunderstorm is in the area. Even a distant rumble of thunder should serve as a warning to get inside a substantial building or hard-topped metal immediately," Jensenius wrote. "The incident also underscores the danger of sheltering under a tree, as images from the scene show victims near a tall tree. Lightning tends to strike the tallest object in the immediate area, which is often a tree."
This story has been updated with additional information.