Bowling Green, Va. ? They were deeply devoted to the Boy Scouts, traveling thousands of miles to the woods of northern Virginia for 10 fun-filled days of fishing, archery and storytelling beside the campfire. One of their first tasks: Set up a large tent.

But the task went terribly awry when they lost control of a giant tent pole and it hit some nearby power lines, killing four Scout leaders as horrified youngsters looked on, said Bill Haines, a Scout executive in Alaska.

Karl Holfeld said his 15-year-old son, Taylor, witnessed the accident and was on his cell phone to his mother back home in Alaska when the electrocutions occurred.

The boys “all started screaming,” Holfeld told the Anchorage Daily News. “He said, `Oh my God, oh my God, the tent is on fire, they’re being burned!”‘

The Scouts spent Tuesday reviewing safety procedures and mourning the deaths of the four men, but said the event would begin Wednesday as planned, with an evening speech by President Bush. A memorial service will be held during the opening ceremony of the Jamboree, which draws more than 40,000 Scouting enthusiasts from around the world.

Scout adviser David Tracewell, 54, of Kansas City, said that the mood “became very somber” as word of the tragedy spread around Fort A.P. Hill – a sprawling Army base about an hour south of Washington.

“These scout leaders : get to know these kids very well,” he said. “I’m sure these kids are devastated. They’re their mentors, their leaders that become like their second dads.”

The dead were identified as Michael J. Shibe, 49, Mike Lacroix, 42, and Ronald H. Bitzer, 58, all of Anchorage; and Scott Edward Powell, 57, of Perrysville, Ohio. Shibe had two sons at the Jamboree and Lacroix had one; the three children all returned home to Alaska.

Bill Haines, Boy Scouts of America Western Alaska Council executive, speaks during a news conference Tuesday in Anchorage, Alaska, concerning the death of four Boy Scout leaders in an electrical accident at the National Boy Scout Jamboree in Virginia. Ron Bitzer, Michael Lacroix and Michael Shibe, all of Anchorage, and Scott Powell, of Ohio, were killed.

Three other adults suffered minor injuries.

The event was closed to visitors Tuesday. Boy Scouts spokesman Gregg Shields gave few details about the accident and was unable to say how long the investigation might take. Army officials are assisting.

“Our hearts go out to the families of these dedicated Scout leaders who gave so much to their sons, their troops and their communities,” Shields told reporters, his voice choked with emotion.