SAN DIEGO -- A magnitude-5.4 earthquake centered 30 miles east of Los Angeles jolted San Diego County Tuesday, but no injuries or structural damage was reported.

The temblor, which occurred at 11:42 a.m., had an epicenter about two miles southwest of Chino Hills in San Bernardino County, according to the U.S. Geological Survey.

Though it caused pronounced ground tremors that lasted some 15 seconds in the San Diego area, the shaker caused no reported local problems, according to law enforcement and public safety officials.

The county Office of Emergency Services went into an alert status immediately after the temblor struck, but got no word of any harm caused by the ground movement, OES spokeswoman Yvette Urrea Moe said.

Over the day, various local agencies -- including Caltrans, San Diego Gas & Electric, the county Water Authority and San Onofre Nuclear Generating Station -- inspected their facilities and reported no damage, according to Urrea Moe.

State personnel were inspecting area dams, she added.

When the quake hit, the 13-story City Hall building in downtown San Diego swayed, and hanging light fixtures in the 13th-floor press room swung back and forth.

The City Council, which was in session at the time of the temblor, took a five-minute recess to assess the situation. The meeting resumed after it was determined the epicenter was not in the San Diego area.

The San Diego Police Department's downtown headquarters building also shook, trembled and swayed, sending some employees out of their offices to make sure them and their co-workers were in no danger.

While apparently causing no significant problems locally, the temblor is "a good reminder for San Diego County residents to review their plan for an earthquake," Urrea Moe said.

The Office of Emergency Services offers forms designed to help families make such crisis preparations. The documents are available for downloading at the agency's Web site, www.ReadySanDiego.org.