On Sept. 18, at 6:30 p.m., an airman dropped a wrench socket as he was working on the upper stage of a Titan II missile with a nuclear warhead based near Damascus, Ark. A fuel leak resulted, and at 3 a.m. the next morning the silo exploded. One airman died in the accident, and 21 others were injured. This is the story of the aftermath of that explosion at one of the nation's oldest missile sites .

The blasts came at 3 a.m. Two rapid explosions blew off the 700-ton steel and cement door above the missile and catapulated its 14-foot-high warhead into the night.

According to witnesses, there was a momentary pause and then a belch of: liquid flame spread out from the hole that had been the silo and rose 200 feet into the air.

Senior Airman David Livingston, who along with Sgt. Jeff Kennedy had attempted to take a fuel vapor reading, three stories down in the missile complex, was just emerging from the ground-level silo door when the explosion occurred.

The force of the blast blew Livingston more than 75 feet, over what had been a 15-foot perimeter fence, to a field beyond. Cement from the demolished silo shot through the air like shrapnel and a piece lodged in Livingston's stomach. The helmet of his safety suit was blown off and he began breathing the deadly vapors of aerozine 50, the Titan II rocket fuel.

Kennedy, who was slightly behind Livingston, was blown 75 feet in a different direction and smacked into a portion of the fence. His side was riddled with cement pellets and his leg was smashed. He, too, inhaled the deadly fuel vapors as he lay against the fence.

The United States' 54 aging Titan II missiles, operational since 1963, have been plagued with more than 100 minor fuel leaks and accidents in the past five years. The Damascus accident, however, is the most serious since a leak at Rock, Kan., in August 1978 took two lives and injured 29 other persons. Three Air Force investigations are now under way; Damascus could turn out to be for the Titan II ICBMs what Three Mile Island became for the nuclear power industry: the disaster that finally forced the government to examine in a serious way what was going on.

The support crew for the entry operation had been gathered at the missile complex perimeter fence when the explosion took place. The force of the blast sent him sprawling. "Hundred-pound cement blocks were falling," one recalled last week, "and red-hot pellets were shooting by."

All the men who had moved to the fence from the access road turn-off, one-quarter of a mile away, were injured, some seriously, most with burns from the ball of flame but others with smashed or broken bones from the flying steel and cement.

Back at the beginning of the access road that led from the highway to the missile site, one officer shouted to the men who had watched the explosion to get into their vehicles and flee.

Many obeyed but a few stayed on, sources said, prepared to go back toward the silo site to gather up the wounded who were calling for help.

It was almost 10 minutes before any communication was established with the men who had been at the perimeter fence. Small fires burned around the complex and the air was cloudy and "smelled like dead fish," one of the wounded recalled.

Twenty minutes after the blast, all the men except Livingston and Kennedy had been accounted for. Most had been carried down the access road to ambulances, leaving two empty vehicles equipped with radios parked at the edge of the now smoldering complex.

At close to 3:30 a.m., Kennedy's voice came over one of those radios.

"Help! Help me! Help me! Can anybody read me?"

Kennedy had dragged himself along the perimeter fence almost one-quarter of the way around the complex to the gate where about an hour earlier his: buddies had been waiting when he had set off toward the silo. Now he found no one there, just the vehicles with their radios. The subsequent conversation was monitored from another point by a reporter for The Arkansas Gazette.

"Yes, we can hear you," was the response to Kennedy's plea.

"Help me!"

"Where are you, Sgt. Kennedy? Where are you, Jeff?"

"Col. [james] Morris [Kennedy's commanding officer, who carried two wounded men from the perimeter gate], I'm down here by your truck, please help me . . . my leg's broken and I'm bleeding. . . ."

Kennedy was picked up within four minutes and several air police then took up the search for the missing Livingston.

It was almost an hour after the explosion, near 4 a.m., sources said, before Livingston was found, put in an ambulance and sent to a hospital in Little Rock.

With the wounded men off the site the next concern was for the warhead. The reentry vehicle -- as it is known to the Air Force -- is as giant-size as its nine-megaton yield (equivalent to nine million tons of TNT, 750 times the size of the Hiroshima bomb).Including its nose cone, designed to protect the bomb on its reentry from space, and equipment that connects it to the missile, what the public calls the warhead was a conical-shaped object 14 feet high and eight feet in diameter at the base.

Shortly after Livingston had been removed an Air Force helicopter carrying radiation detection equipment headed toward the complex, which still was marked with occasional fires. By 5 a.m. the fires died out and specially trained radiation detection teams began to move up the access road through the darkness seeking any indication of a radiation leak. At that point, no one knew what had happened to the warhead in the explosion and the fires that followed.

Shortly before 6 a.m., the radiation team decided to halt operations until daylight.

Within an hour, information was received, sources said, that sent a shudder through the entire Air Force team that was monitoring the accident. A report came in from Little Rock Air Force Base, sources said, that several of the injured men had been found to have extremely low levels of radioactive alpha particles on their boots.

By 7 a.m. the radiation detection crews started up again and made their way up the access road almost to the site of the perimeter gate without detecting any sign of radioactivity.

According to sources, the first sighting of the warhead came at 7:30 a.m., more than 4 1/2 hours after it had been catapulted from the silo. Shortly after its discovery it had to be covered by a tarpaulin because a helicopter hired by one of the local television stations was circling over the site.

Initial inspection of the warhead found that the nose cone had cracked its metal sides had been dented, but on the whole it was intact. Most importantly, there was no indication of any radiation leak. Later in the day, a special X-ray machine was used on the warhead and its internal workings were said to have survived the explosion.

For days the Air Force refused even to acknowledge there was a warhead on the missile when it exploded, giving rise to rumors it had not been found and allowing speculation that there was the possibility of radiation leaks.

The source of the alpha particle radiation on the injured airmen is still considered a mystery, according to Air Force officials.

While the site was being worked over, Airman Livingston was undergoing surgery, having the chunk of cement removed from his stomach and his broken leg assembled and put in a cast. The operation was a success, but thereafter the effects of the fuel vapors began to work and suddenly his lungs collapsed. He died less than 24 hours after the blast.