A strong earthquake shook this desert community yesterday, destroying at least seven buildings and damaging more than 600 others, cutting off water supplies, damaging an irrigation canal and causing a road to "just sink out of sight."

No injuries were reported.

"It's a miracle no one was hurt," Mayor Ron Rodriguez said of the quake which registered 5.6 on the Richter scale and jolted people out of their beds in this community of 1,600.

The quake, which struck at 5:09 a.m. PDT, caused extensive damage to this community, where many structures are built from adobe and red brick. Adobe is sun-dried clay.

Demolition crews were busy yesterday afternoon leveling two badly damaged adobe and stucco commercial buildings which had been condemned as safety hazards.

Thirteen other commercial buildings were damaged, as were 70 percent of the town's 900 homes. Half a dozen mobile homes were knocked off their foundations and a bell crashed 20 feet to the ground from the steeple of St. Joseph's Church.

Sunday's was the largest in a "swarm" of about 40 quakes above magnitude 3.0 that have rattled this area since Friday evening. Hundreds of smaller quakes also were recorded.

The quake was felt in a wide area of Southern California, from San Bernardino on the north, to Calexico on the Mexican border to San Diego on the coast. Slight tremors were barely felt in Yuma, Ariz., 55 miles southeast of here.