A third person who was seriously injured by a lightning strike at the White House on Thursday has died in a hospital, US news channel CBS reports. A fourth person is still in critical condition in hospital.

    Among the three dead was an elderly couple from the state of Wisconsin. They celebrated their 56th wedding anniversary in the US capital. The other person who died is a 29-year-old man. His identity has not yet been released, as his next of kin have not yet been notified.

    The four victims were found around 7 p.m. local time on Thursday in Lafayette Square park next to the White House, a few dozen yards from the statue of former President Andrew Jackson. The fact that the victims initially survived is partly due to the rushing American secret service, a fire service spokesperson said earlier. He advises people against taking shelter under a tree during a thunderstorm. “That’s just a very dangerous place to be.”

    A severe thunderstorm warning was issued in Washington on Thursday evening. An eyewitness told the American newspaper that the lightning strike and ensuing blow were “huge”. “The whole area shook, it was literally like a bomb went off, that’s what it sounded like.”

    Every year, an average of 23 people in the United States are killed by lightning.