Four people were critically injured following a lightning strike Thursday evening in Lafayette Square, just north of the White House, authorities said.

The four patients, two men and two women, were all taken to area hospitals in critical condition with life-threatening injuries, Vito Maggiolo, a spokesperson for the District of Columbia Fire and Emergency Medical Services Department, said in a Thursday evening news briefing.

The lightning strike was reported at 6:52 p.m. The victims were near a statue of Andrew Jackson, Maggiolo said, adding that “it appeared they were in the vicinity of a tree.”

Uniformed Secret Service agents and U.S. Park Police officers who were in the area and witnessed the strike provided first aid to the victims, Maggiolo said.

“Their agents, their officers, witnessed this lightning strike and immediately began to render aid,” Maggiolo said.

It’s unclear exactly what the victims were doing at the time.

“All we know for sure is that there was a lightning strike in their immediate vicinity, and all four were injured,” he said.

A CBS News camera that was recording on the White House North Lawn around the time of the lightning strike captured the powerful rumble of the thunder.

“The thunder was so loud, @gabrielle_ake and I jumped up in fright,” CBS News chief White House correspondent Nancy Cordes tweeted. “‘That’s too close – we’re shutting down’ advised photographer Ron Windham.”