SAN BERNARDINO, Calif. -- A moderate earthquake shook an inland area of Southern California near San Bernardino on Tuesday night, giving a start to thousands across a heavily populated area.
There were no immediate reports of damages or injuries, however.
The U.S. Geological Survey says in a preliminary report that the magnitude-4.4 quake hit in foothills northwest of San Bernardino about 5:38 p.m. at a depth of about three miles. Minutes later it was followed by aftershocks of magnitude 3.8 and 3.2.
People reported feeling the earthquake throughout the suburbs east of Los Angeles, which is about 50 miles southwest of the epicenter.
Tim Frank, a dispatch supervisor with the San Bernardino County Fire Department communication center, said there were no initial reports of damage or injuries, but the shaking was felt "numerous times" at the department.
"It was like a big truck was coming in," Frank said.
Police in the area also said they had no reports of problems from the quake.
The quake came near the intersection of the San Jacinto, San Andreas and Cucamonga faults, three of the largest in Southern California, but it was too small to determine which fault was responsible, the USGS said.
There have been nine earthquakes above magnitude-4 In the general area in the last 10 years.
"If you have damage from this, you have a pretty bad house," Lucy Jones, a seismologist at Caltech in Pasadena, told CBS Los Angeles.
Los Angeles County Fire Department stations immediately went into earthquake mode, meaning they roll equipment outside to keep it safe from possible falling debris and to keep it from being trapped inside in case it is needed.
Traditionally earthquakes of this size are a monthly occurrence in Southern California, but "it's been quieter for the last few years," Jones said.
There is a five percent chance that the quake, or any quake, is a precursor of something bigger, Jones said.