Workers for private contractors made several hundred calls to sex lines when they should have been cleaning City Hall or providing security.

Mayor L. Douglas Wilder promised a shakeup after learning of the calls, and an incident in which a contract employee allegedly broke into a courthouse office.

"We are not without fault," Wilder said at a news conference Tuesday.

Deputy Chief Administrative Officer Harry E. Black said the calls were to local numbers. The primary cost to the city, he said, was work that was not performed.

Last week, a custodial worker with a criminal record allegedly broke into an office at the John Marshall Courts Building.

The company that employs him failed to submit his name in advance to the city as required under security procedures in the contract.

The employee worked for one of three firms that city officials said provided night custodial or security workers.

Wilder learned of the calls and the arrest when he arrived at City Hall after the Labor Day weekend.

The mayor said city officials would study the contracts to see if they can be terminated or if any other sanctions can be invoked. They also will investigate the oversight of the contracts by city employees.

Wilder said the latest public works embarrassments illustrate chronic management problems at the department that oversees trash pickups and operates a fleet of thousands of vehicles.

A number of department officials have already been fired because of problems identified in an audit of the fleet management system.

The audit faulted the Wilder administration for easing controls over fuel cards used to gas city-owned vehicles, poor record-keeping, and hiring a fleet manager who already was under criminal investigation in another state.

The manager since has been indicted here for allegedly obtaining money by false pretenses.