Over a five-day span this month that many Americans think of as a long weekend, seven construction workers were killed in three separate accidents across the U.S.

Three workers, employed by two different subcontractors, died Aug. 5 when a pre-cast concrete wall collapsed at a Home Depot being built in Greensboro, N.C. "It was right around lunch time and they were taking a break sitting outside the wall when it fell," says Leslie Lejeune, a Greensboro detective. She says the 35-ft-tallx20-ft-wide section, weighing about 80,000 lb, was not shored or connected to the roof. The workers were identified as Larry M. Thompson III, 22, and Juan Almaguer, 34, both of Winston-Salem, and Rickey C. Smutko II, 24, Germanton, N.C.

In Snellville, Ga., three workers erecting a billboard were killed Aug. 1 when the structure collapsed, clipping the roof of a nearby shopping mall. Another worker was injured and pulled from the wreckage by rescue workers. "They were putting the slats in a changing billboard when the sign apparently broke near the top weld," says David A. Dusik, a Gwinnett County police officer. "Two cranes were brought in to stabilize the site and airbags were used to lift portions of the sign to effect the rescue." Dusik says the sign weighed about 35,000 lb and was mounted on a single shaft.

The accident follows a recent court-ordered overturning of a ban on signs in Snellville, upholding a lawsuit by two advertising firms. But the city has since imposed a moratorium on signs "in excess of the size and height specified in our current ordinance."

Also on Aug. 1, a 20-year- old construction worker was crushed by a crane boom while preparing it for transport in Admire, Kan., near Emporia. Conrad Grant Carlson, Osage City, Kan., was trapped under the boom at the site and found dead by a co-worker, says D.J. Lopez, Lyon County deputy sheriff. "Apparently he had removed pins from the bottom of the boom and it came apart and crushed him," says Lopez. The names of all of the workers employers could not be confirmed at ENR press time.