A couple in their 70s celebrating their anniversary and a 29 year-old man have died after a lightning strike near the White House during a storm Thursday evening, authorities said. One other person is hospitalized with life-threatening injuries.

The lightning struck just before 7 p.m. in Lafayette Park across the street from the White House, according to the D.C. Fire and Emergency Medical Services Department. 

James Mueller, 76, and Donna Mueller, 75, both from Janesville, Wisconsin, died from their injuries, Brianna Burch, spokesperson for the D.C. Metropolitan Police Department, told USA TODAY.

The third victim, the 29 year-old, was pronounced dead Friday. The fourth person, a woman, was in critical condition, police said. Their identities were not immediately released.

Authorities did not reveal how the people were injured, other than to say they were critically hurt in the lightning strike.

“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. 

All four were transported to hospitals with “critical life-threatening injuries,” D.C. Fire and EMS said in a tweet Thursday.

Spokesperson Vito Maggiolo said the lightning strike was witnessed by members of the U.S. Secret Service and the U.S. Park Police, who responded to the scene, D.C. Fire and EMS spokesperson Vito Maggiolo said. 

Parts of the D.C. metro area were under a severe thunderstorm warning Thursday evening, according to the National Weather Service.

James and Donna Mueller were celebrating their 56th wedding anniversary with a trip to the nation’s capital when they died, said Michelle McNett, the couple’s niece. She remembered them as high school sweethearts who loved to dance and host gatherings for their close-knit family.