3 dead, 1 in critical condition in lightning strike near White House

Two Wisconsin residents celebrating their wedding anniversary died following a lightning strike near the White House on Thursday night, police confirmed to ABC News Friday.

A third victim -- a 29-year-old man -- has also died in the incident, police said Friday afternoon. A fourth person is still in critical condition following the lightning strike, police said.

Police said 76-year-old James Mueller and 75-year-old Donna Mueller, both from Janesville, Wisconsin, died after being injured in the strike in Lafayette Park in front of the White House.

Metropolitan Police Department Chief Robert Contee confirmed Friday that the Muellers were married and Madison.com reported they were in Washington to celebrate their 56th wedding anniversary.

The third victim was identified by police on Saturday as Brooks Lambertson, of Los Angeles. He was in Washington, D.C., on business, according to his employer, City National Bank.

"Brooks was an incredible young man who will be remembered for his generosity, kindness and unwavering positivity," the company said in a news release. "His sudden loss is devastating for all who knew him, and his family, friends and colleagues appreciate the thoughts and prayers that have poured in from around the country."

Lambertson was a vice president at City National Bank, where he managed sponsorships, the company said. He lived in downtown LA and was an "avid sports fan."

Thursday night, D.C. Fire and EMS said it had responded and was treating four patients found in "the vicinity of a tree."

It said the two men and two women were transported to area hospitals with "life-threatening injuries."

Officials said it's still unclear what the adults were doing prior to the lightning strike and why they were in the park.

White House press secretary Karine Jean-Pierre expressed sadness Friday morning following word the two Wisconsin residents had died.

"We are saddened by the tragic loss of life after the lightning strike in Lafayette Park. Our hearts are with the families who lost loved ones, and we are praying for those still fighting for their lives," she said in a brief statement.

Uniformed U.S. Park Police officers and members of the Secret Service were also on the scene and immediately rendered aid to the victims, an EMS official said during a news conference.

The National Weather Service had issued a severe thunderstorm warning for the area Thursday evening.

ABC News' Beatrice Peterson, Davone Morales, Molly Nagle and Caleigh Bartash contributed to this report.