Lightning struck a group of Boy Scouts taking shelter from a storm, killing the troop leader and a 13-year-old boy in the latest tragedy to befall the organization this week, authorities said.

The teen, Ryan Collins, died Friday night at the University Medical Center in Fresno, said hospital spokeswoman Mary Lisa Russell. He had been kept alive for a day on a ventilator so his organs could be donated, his family said.

The assistant scoutmaster, Steve McCullagh (search), 29, was killed instantly when the bolt made a direct strike on a tarp the Scouts had set up in a meadow in Sequoia National Park on Thursday, the coroner's office said.

"He didn't even make it off the mountain," said Sue Collins, the boy's mother, crying along with her husband and younger son at the hospital. "It's horrible. It's a fluke."

Six others were injured.

The lightning strike came just days after four Scout leaders were electrocuted while putting up a tent at the National Scout Jamboree (search) in Virginia. Dozens of Scouts were sickened by the stifling heat two days later at the jamboree.

At least one of the injured in the lightning strike was kept alive only because the troop managed to administer CPR for an hour, park ranger Alex Picavet said. It is not known which injured person that was.

"That's amazing," Picavet said. "It's very difficult. It's probably because of their Boy Scout training."

One troop member was being kept for observation at the Fresno hospital, and all the others were treated and released from another hospital, authorities said.

The scout group from St. Helena (search), which included five adults and seven teenage scouts, had been camping for a week as part of a nine-day backcountry hike along the John Muir Trail.

Two teenagers ran 25 minutes to a ranger station after the strike, and five helicopters flew in to evacuate the group.

"They did the best they could in the situation they were in," Picavet said. "They didn't have metal poles, and stayed away from high points."

Bill Collins said his grandson was a scout for more than three years and loved the outdoors.

"He was a fabulous boy. He was doing what he loved to do," Collins said. "It's just a tremendous shock to everybody."