As officials across the Washington region continued to assess the damage from a 5.8-magnitude earthquake, structural engineers warned that the full effect of the quake might not be known for days.

While the area seems to have fared relatively well, Tuesday’s earthquake packed a punch, toppling pinnacles at the Washington National Cathedral, displacing more than 500 residents of two Prince George’s County apartment buildings and inflicting damage at dozens of schools in Fairfax County.

But more damage is likely to be uncovered in coming days, engineers and others said.

Small cracks can lead to big problems over time. Gas leaking from snapped pipes is among the most serious concerns, and utility companies urged residents who smell gas to evacuate their homes immediately and call 911. They also urged people to look for cracks in drywall, shifting foundations and tiny leaks in water pipes.

Insurance officials also warned that homeowners with quake-related damage might not be covered because standard policies don’t include an earthquake provision.

Across the region, walls cracked and chunks of concrete broke off buildings. But thanks to improvements in building design and codes that require reinforcements that help buildings stay upright when the ground starts rumbling, the damage was minimized.

Many of Washington’s buildings are big, solid structures that can take a good shaking up. Some older buildings, designed when earthquakes were not a concern for architects, have been retrofitted to better withstand vibrations.

“We’re well suited in this area for the magnitude of earthquakes that are going to occur here,” said Henry Green, president of the National Institute of Building Sciences. “A 5.8 is larger than we would typically expect but not devastating.”

Bridges, however, might be another concern, said Yunfeng Zhang, an associate professor of civil engineering at the University of Maryland, who noted that “because of the shaking, the bridge girder might slip a little away from the original position.”

At the Capitol, which is made of sandstone and marble with a cast-iron dome, building inspectors were looking at all of the structures in the complex Tuesday.

“At this point, we’re still doing assessments of each of the buildings, but we’re not seeing major structural damage at this time,” said Eva Malecki, a spokeswoman for the Architect of the Capitol. “These are historic buildings. They’re built to last.”

Engineers were working to make sure the Washington Monument survived the earthquake. Park officials said that the top of the 555-foot-tall stone obelisk appeared to have cracks and that the structure would remain closed pending a top-to-bottom inspection.

Park Service spokesman Bill Line emphatically denied a broadcast report that the monument was listing to one side.

“We do know that the Washington Monument is not leaning,” Line said, as mounted Park Police officers kept pedestrians away from the monument grounds. “But safety concerns are paramount, and the structural engineers are checking it out right now.”

Line could not say whether the monument, which is reportedly the tallest free-standing masonry structure in the world, has been reenforced for earthquake-resistance.

“We do adhere to the highest engineering standards, but this area is not California,” he said.

Reports of damage across the area included three fleurs-de-lis-shaped capstones that fell from corner spires of the Washington National Cathedral’s central tower.

Reached by cellphone as he was climbing to the top of the cathedral, mason Joe Alonso said that the tower, which is the highest point in Washington, “has sustained some pretty significant damage to the pinnacles.”

In Fairfax County, principals at 74 schools reported some earthquake damage, spokesman Paul Regnier said. Each school was being inspected to determine whether repairs are needed. Fairfax students do not return to classes until after Labor Day.

In Prince George’s, a shelter was being set up for hundreds of residents of badly damaged apartment buildings in Temple Hills and Hillcrest Heights, officials said.