Harbor Freeway Closed by Bomb Threat : Transportation: Bag hanging from girder holds only bolts. Three-hour shutdown between King Boulevard and Florence Avenue affects 40,000 motorists.

Midday traffic on the Harbor Freeway was stopped for almost three hours Tuesday after construction workers found a suspicious-looking bag hanging from a girder during a search prompted by two bomb threats.

The cloth sack turned out to contain only bolts, police said.

After the threats to the C. C. Meyers Corp., an employee saw the bag tied by wire to a construction truss near the freeway overpass at 54th Street and Grand Avenue. As a precaution, shortly after 10 a.m. police and California Highway Patrol officers closed a one-mile section of the freeway between Martin Luther King Jr. Boulevard and Florence Avenue.

Fifty highway patrol and police officers--including a bomb unit--joined construction workers and Caltrans employees in searching the area. A suitcase found on the roadside also contained no explosives.

The threats made to the freeway contractor’s office did not specify a location for the bomb, forcing inspection of all sites between Vernon Avenue and the Riverside Freeway where C.C. Meyers is working on an elevated stretch of freeway.

About 40,000 motorists were detoured between the 10 a.m. shutdown and 1 p.m., when the freeway reopened, said Officer Rhett Price, spokesman for the California Highway Patrol. Streets remained congested for another hour.

Officials of the Sacramento-based C. C. Meyers Corp. notified police of a call “from an anonymous male” to a branch office in Gardena at 7:45 a.m. Another threat came an hour later, said Greg Allen, project superintendent. “The first one we didn’t take too seriously,” Allen said. “The second time, we were concerned. He seemed like a persistent person.”

Police had not determined a motive for the threats. But several workers said the calls may have been made by someone familiar with the company. They said it seemed unusual that the calls went to the company’s branch office, because the phone number is not listed in the directory for Los Angeles, nor is it displayed at construction sites.