In 1950, Virginia National Guardsmen training in downtown Richmond loaded a high-powered gun and fired. The next day's Richmond Times-Dispatch called it "the shot heard'round most of Richmond."

The gun went off at 9:10 p.m. during an Oct. 30 drill inside the Richmond Light Infantry Blues Armory at Sixth and Marshall streets. An instructor and seven guardsmen with the 1st Battalion's 176th Infantry Combat Team had assembled to practice loading and firing a 75 mm recoilless rifle, a powerful gun on a tripod base developed during World War II.

The men drew a shell labeled "dummy," believing it to be inert ammunition that could not leave the gun's chamber when fired. "We aimed it at first toward a room where some of the officers were meeting," one of the guardsmen told The Times-Dispatch. "But then somebody laughed and said it wasn't polite to aim at the staff, even if the shell was a dummy."

As soon as the shell was in place, the instructor shouted, "Fire!"

"Blues Armory was rocked," the next day's Times-Dispatch said. "More than 100 windows were shattered." The shell, described in some reports as almost 3 inches in diameter and about a foot long, breezed through a 4-inch interior wall and exited through a second-floor window. It followed Marshall Street along an eastward trajectory.

The reverberations and whine of the missile as it screamed down Marshall Street just yards above street level brought crowds running. "A meeting of the school board at Ninth and Marshall streets came to an abrupt halt when the projectile passed -- evidently just outside the window," said The Times-Dispatch account.

The shell followed Marshall Street for more than a mile before finding a target. It struck with such force that it needed several more impacts to halt its progress. The Richmond News Leader described the strikes as "the shelling of Church Hill."

The shell first slammed through the roof of a porch on a house at 2214 E. Marshall St. "It plowed a foot-long hole through the roof and emerged near a front-porch post," The Times-Dispatch said. It then sailed across the front porch of the house next door, destroying a glider cushion on its way and passing within feet of an infant asleep in a first-floor front room.

The shell continued on a path that took it beneath the porch of the next house, where it knocked out wooden supports. Its final target was the porch at 2220 E. Marshall St., built lower than the others. There, it destroyed a swing and splintered a post. It then landed in the street, rolled and came to rest beneath a parked car, where it remained until police and military officials quickly arrived to retrieve it.

The shell never exploded, and with the exception of one guardsman cut by flying glass at the armory, no one was hurt. "We must be leading a good life," said a resident of the shell-shocked neighborhood.

Two investigations immediately got under way -- one by the 1st Battalion, and the other by the U.S. Army. The guardsmen insisted they had used a shell labeled "dummy." But when an Army investigator arrived in Richmond two days after the incident, they were stunned at what he told them.

"There are no 'dummy' shells manufactured for this relatively new weapon," said a Times-Dispatch report. "The nearest thing to a 'dummy' shell," The News Leader explained, "is a practice round, containing no explosive charge, such as the one which went hurtling through a Blues Armory wall." The "dummy" label on the shell that hit Church Hill referred to its detonation capabilities, not its propellant charge.

Five weeks after the accident, results of the investigations were released, and both studies concluded the Army's labeling practices were at fault and in need of changes.

A Dec. 6 Times-Dispatch editorial decided the episode may have been a blessing. "If the shell marking system is improved," the editorial said, "the Blues Armory incident may have served a useful purpose in preventing a serious tragedy somewhere in the nation."