Unearthing of Bomb ‘Blanks’ Spurs Warning

Residents of Orange County’s newest community, Rancho Santa Margarita, have been warned to be on the lookout for World War II-era “target markers” buried in their yards, but so far none has been sighted.

The Marines formerly used the bomb-shaped devices during aerial bombing practice. “It was like using blanks,” Santa Margarita Co. spokeswoman Joan Condino said.

The Marine Corps used a 503-acre section of the flat plain, called the Plano Trabuco, near Saddleback Mountain from about 1944 to 1956 for target practice, Condino said, citing information Santa Margarita Co. has obtained from the military. The Plano Trabuco makes up most of what is now the 5,000-acre Rancho Santa Margarita community, located in southeast Orange County, between Mission Viejo and Coto de Caza.

The target markers are of two types, she said. One is an eight-inch-long, snub-nosed, hollow-core device that contained a charge that, when ignited, expelled a powdery substance resembling smoke.

A device similar to this variety was found last April at John Wayne Airport and caused the runway to be evacuated until it was removed and found to be non-explosive.

The second kind, Condino said, is a practice rocket with a pointed tip that contained no charge. “They were completely inert. They just were dropped from the aircraft and did not explode, ignite, fragment or do anything. They just were dropped.”

For years after the target practice, the Santa Margarita Co. used the property only for ranching and farming, and as workers uncovered buried target markers, “they would stockpile them without incident,” Condino said.

But in 1984, the company began developing the property. It contacted the Marine Corps and asked it to remove the stockpiled target markers, as well as perform an electronic sweep of the area with a metal detector. The Marines removed 6,000 pounds of the devices before development began, Condino said. During grading for the residential area of the community--several miles northeast of the target area--not a single device was unearthed, she said.

But recently, during construction of a business park--located between the residential section and the target area--target markers were dug up. One was found eight feet deep.

“Because it was not just one, but two, we decided to send a letter to our residents,” warning them to be on the lookout, Condino said.

Most of the markers found earlier by the Marines were of the inert variety, but even the ones with the ignitable charge probably were rendered “duds” through rust after being buried and rained on for 40 years, she said.

Nonetheless, the letter asks that, if any target markers are found, residents call the Santa Margarita Co., which will arrange for the Marines to dispose of the devices, she said.