WE GOT A RUMBLE that originated more than 200 miles away yesterday, but what if Philadelphia absorbed the full brunt of a 5.8 magnitude earthquake?

Most buildings would ride out such a quake just fine, while older, less solid structures could be in for a hurtin', according to structural engineers around town.

"I would suspect that buildings in disrepair would have problems, but probably not buildings in good repair," said Brad Landis, co-owner of Larsen & Landis, a structural-engineering firm with offices here and in Wilmington, Del.

"If we had a bigger earthquake like Japan has, we certainly would have problems because a lot of the older buildings are not built up to the code that they are now," Landis added.

"I'm not worried about a modern building, but I suspect that if we had a 5.8 earthquake in Philadelphia, there would be collapses of older buildings and rowhouses," said Constantine Doukakis, a principal at Keast & Hood Co., a structural-engineering firm in Old City.

Doukakis said that his fourth-floor office swayed in the Curtis Center, built at 6th and Walnut streets in 1926, but it stood firm.

He's not so sure that buildings and homes built in the 1700s and 1800s would hold up as well if the city suffered a direct quake hit.

Structures built before 1870 were constructed using lime and sand but not concrete, making for softer mortar, said Doukakis, who noted that such buildings can be found in older neighborhoods such as Queen Village and Society Hill.