The lightning apparently entered the cabin through some large nails near Ostler's bunk, witnesses said.
Three other Scouts in Ost- ler's Troop 56 from Salt Lake City suffered minor injuries in the lightning strike.
Ian Filiaga, age unknown, and Kurtis Loosli, 13, were taken to University of Utah Medical Center by helicopter. They were reportedly in good condition Wednesday. Matthew Edwards, 13, was taken by ambulance to Primary Children's Medical Center, where he was treated Wednesday and released.
The other two Scouts of Troop 56 and their leaders were not injured.
Edwards' father, Doug Edwards, who was at Camp Steiner, said the Scout party noticed storms in the distance about 8:30 p.m. A short time later, light rain began to fall.
About 90 minutes later, as the Scouts settled down for the night, they heard a loud explosion - "like a stick of dynamite going off inside the cabin," Edwards said. There was no light, no warning, he said.
Despite efforts of nearby Scouts and their leaders, including two physicians, Ostler did not regain consciousness and is believed to have died instantly.
Willis Orton, a Scout leader with Sandy's Troop 93, was in the shelter next door and saw the lightning bolt hit Ostler's cabin.
"He was sleeping right where the lightning arced into the cabin," Orton explained, fighting back tears. ''They screamed, 'Help us! Someone is down.' "
Orton immediately administered CPR. Within minutes, Stephen Morris, who is director of the Trauma Center at University hospital, arrived from his nearby camp with Sandy Troop 730 and took over CPR efforts.
"We got his airway cleared quickly and began mouth-to-mouth resuscitation, but there was no pulse," Morris said.
Morris, along with Morris Matthews, a Cottonwood Hospital anesthesiologist affiliated with Troop 730, continued CPR as the Scout was moved to a lower parking lot where helicopters would land.
"We continued CPR in the pickup on the way down," Morris said. "An IV was started and medications were given. But one hour and 15 minutes later, we could see he was in full [cardiac] arrest."
The boys were where they should have been during a storm, said Matthews.
"It's so bizarre," Matthews said. "When it was over, I just sat down on my bunk and cried for a half-hour."
Jeremy Robinson, the father of a Scout from Troop 910 who was sleeping in the next cabin, said the two uninjured Scouts from Troop 56 were visibly shaken by the incident.
"They were in disbelief," he said. ''They just kept saying, 'I can't believe it. I never thought it would happen to us.' They wanted to know how their friend was doing. They kept asking, 'Is he going to be all right?' ''
Robinson's son and others in Troop 910 returned to their Bountiful homes Tuesday night. "They were scared. They were really scared," Robinson said. "They just wanted to get home."
Scouts from Troop 730, who were camped about 100 yards from the lightning strike, found the incident difficult to take in.
"We're feeling bad," said 15-year-old Nate Freea. "It's like, things happen and you have to move on."
Alex Eliason, a 13-year-old Scout said, "We thought, oh man, that was close. But you never think it can happen to you."
During the 75-year history of Camp Steiner, at 10,400 feet believed to be the highest Boy Scout camp in the United States, this is the first time a Scout has died from lightning, said Paul Moore, the CEO of the Great Salt Lake Council of the Boy Scouts of America.
The Adirondack-style cabins are open to the elements on just one side. But Scout leaders put a shroud over Lake Camp II, the cabin where Ostler was struck, out of respect for the boy, Moore said.
"We really feel it would be too traumatic for those involved to see the image in the media," he said.
About 200 Scouts and 50 leaders were at Camp Steiner for a week of merit badge classes and fun. Most have remained at camp after the accident.
"There is a real appreciation and sorrow for what's happened," he said. "But the boys are going on with activities."
In a brief news release, Paul Ostler's parents described him as a loving child who had the ability "to bring a smile to everyone's face."
Ostler, who would have have been a sophomore at East High School this fall "will be missed more than you can imagine," the family stated.
Edwards choked up when he began to speak about Ostler, who he said was his son's best friend. Edwards' 10-year-old daughter, Sydney, began to weep.
"This was an extremely traumatic experience for these boys," Edwards said. "The loss of Paul Ostler is so painful for all of us that I cannot bear to go into great detail."
Tribune reporter Nate Carlisle contributed to this story.