COLUMBIA — U.S. 63 was closed in both directions for about 90 minutes Monday when workers at a construction supply company near the area found a box with seven sticks of dynamite.
Workers were outside cleaning up scrap metal at APAC Missouri Inc., 1591 Prathersville Road, when they discovered a 4-foot-by-4-foot unlabeled box.
When the workers opened it, they found the dynamite along with blasting caps and a detonation cord, Boone County Fire Protection District Division Chief Gale Blomenkamp said.
"The explosive materials are possibly 25 to 30 years old, which is longer than APAC has owned the facility," a company news release stated.
Two Mid-Missouri bomb technicians and seven members of the Boone County Fire Protection District were dispatched to the area at 11:33 a.m.
The Boone County Sheriff's Department and Missouri Highway Patrol also responded to the incident.
The decision to close the highway was made "due to the proximity to the explosives," Blomenkamp said.
The explosives were rendered safe by bomb technicians at about 3:30 p.m., according to Blomenkamp.
APAC does not use explosives at the facility and was unaware of the dynamite, the company news release said.
An investigation is under way to determine how the box came to be on APAC's property.