Salt Lake police and the Salt Lake County attorney's office are investigating why one youth died and three others were injured during a rock concert Friday night in the Salt Palace.

Killed during the performance of the heavy-metal band AC/DC was Jimmy Boyd, 14, 1501 S. 400 East, Salt Lake City.Curtis Child, 14, remained in critical but unstable condition Saturday night in Holy Cross Hospital, while Elizabeth Glausi, 18, of Provo, was upgraded to "critical but stable."

Also injured at the concert was Brandy Burton, Glausi's roommate, who was treated at LDS Hospital, then released, said Salt Lake police Lt. Mark Zelig.

The victims were injured when they were compressed within a crowd of fans on the main concert floor in the Salt Palace's Acord Arena.

The death is the first in Utah rock concert history.

"It looks like (Boyd) died of asphyxiation from being crushed by an enthusiastic crowd," Zelig said.

An autopsy performed Saturday determined that Boyd died of asphyxiation, police said.

There were no signs of trauma to the victims' bodies, and preliminary blood tests revealed no sign of drugs, Zelig said.

Witnesses described a hellish scene of heat, youngsters passing out and crowds of thousands surging forward, with security guards fighting to extract people needing medical attention.

Concertgoer Troy Drake, of West Valley City, gave cardiopulmonary resuscitation to two of the victims for 15 to 20 minutes.

"They were gray; they had no pulse."

The trouble apparently started about 9 p.m., three songs into the concert, when youthful fans crowded forward, trying to get as close to the stage as possible.

Though seats were reserved in the dress circle, the main floor had "festival style" seating - in other words, no seating.

"We've been critical of the `festival style' for years, and they haven't listened to us," said a police officer who asked not to be identified.

Drake, who estimated the temperature at 100 degrees, said he believes some of the people on the floor fell and were trampled.

"Down on the floor the heat will get you quick," Drake said. "You could get 400 or 500 people packed that tight, and someone falls, nobody sees them fall."

According to police Lt. Marty Vuyk, the victims were discovered while security guards responded to another person needing medical assistance in another area.

"When the house lights were illuminated, the four victims were found on the floor," Vuyk said.

Some of those who fainted were passed "like a rag doll" above the crowd and to the side until medical help arrived, Drake said.

"The people I worked on, when they pulled their clothes off, were soaking with sweat," Drake said.

He said he saw paramedics use electroshock paddles on one of the boys. "I didn't see any response from him."

The other boy whom Drake tried to help had "no signs of life whatever. . . . To me, they were gone."

Jean Watkins, a Deseret News staff writer assigned to review the concert, said that by the time she retrieved her tickets, the gate count was around 13,200, and tickets were still being sold.

"It was standing-room only on the main floor," she said.

She counted 11 security officers in yellow jackets around the stage and about four among the crowd on the floor.

As the concert progressed, guards began throwing gallons of water on the crowd from large white containers, trying to cool off the fans.

Kris Fannin, a Salt Lake woman who attended the concert, said, "There were a great amount of people who were pretty out of it (intoxicated), especially the crowd on the floor. There was no crowd control and few security guards.

"People were body to body. Nobody could get through to the person who fainted. If anybody in the crowd did fall down, they were trampled."

In an unrelated incident, Larry Mitchell, 25, suffered head injuries when he tried to jump from a stairway to an escalator outside the arena. He slipped and landed in the pool of a fountain, Vuyk said.

Mitchell, address unknown, was discovered lying submerged in about two feet of water. A woman passer-by pulled him from the fountain and administered first aid until help arrived. He remained in satisfactory condition Saturday in LDS Hospital.