Grantsville, UT Factory Explosion, July 1981


Grantsville, Utah (UPI) -- Federal agents say they may never know what triggered three explosions that disintegrated a mining detonator factory and its five workers, leaving only a moon-like crater of rubble on the western Utah desert today.
Tooele County Sheriff Walt Shubert said rescuers found "not a trace" of the three teenagers and two adults working the graveyard shift at the Mining Services International plant early Thursday when it exploded in a fireball, spewing jagged steel and concrete rubble up to 1 1/2 miles away.
"We estimate the first blast had the force of 15,000-20,000 pounds of explosive -- the equivalent force of 14 tons of TNT. They never knew what hit them," said Nick Dereta, agent in charge of the U.S. Bureau of Alcohol, Tobacco and Firearms in Utah.
When ATF agents dared to approach the fiery scene, all they found was a smouldering moon-like crater 45 feet deep and 150 feet long.
Because of the destruction, Dereta said the cause of the three blasts may never be determined, although authorities believe they were probably accidental and may have originated in the chemical mixing area.
Another ATF agent, Warren Wheeler, said the blasts might have been touched off by a lightning storm that buffeted the region 50 miles west of Salt Lake City during the predawn hours Thursday.
The plant, located 8 miles from the small farming community of Grantsville, manufactured a high-intensity explosive used as a "booster charge" to ignite blasting material for mining.
The booster is 1.4 times as powerful as TNT, Dereta said.
MSI Vice President Robert Mouritsen said the factory "was a modern facility, equipped with every conceivable safety device" and President Steven Brockbank said firm officials were shocked by the accident.
All the victims lived in Grantsville, which has a population of just 3,000.
"I can't remember anything that comes even close to this," said Larry Harrison, a resident for 16 years and coach at Grantsville High School.
"This is a tragedy no matter what. But when it hits a community the size of Grantsville, there isn't anyone who isn't touched by it."
One of the victims, PHILLIP DIDERICKSON, 18, had just graduated from high school in June after winning state titles in football, baseball, basketball, tennis and track.
The other victims presumed dead in the explosion were identified as JEFF BOYER, 19; GARY GILBERT, 19; RICHARD HIGLEY, 48; and JEANNE MABEY, 51.
Horrified officials who arrived at the scene first said the 4,000-square-foot main building vanished in the blasts, which began about 4:19 a.m.
The initial explosion, and two others at 6:45 a.m. and 7 a.m., turned nearby cars and heavy trucks into smoking junk. Residents in Grantsville, 8 miles away, were jarred from their sleep.
A huge fireball shot into the sky, and was spotted by several commercial airline pilots.
Lorrie Sandberg, 20, was scheduled to work the graveyard shift the night of the disaster, but called in sick.
"I feel very lucky, but at the same time I feel very terrible about it," she said. "It hasn't really hit me yet, and I don't think it will for a long time."
"As soon as I heard about the explosions and the deaths, I took a minute to pray in thankfulness -- and for those who lost their sons, mother and husbands."

Roswell Daily Record New Mexico 1981-07-31