Preliminary magnitude-4.4 earthquake rocks South Pasadena

Many parts of Southern California felt shaking Monday afternoon as a preliminary magnitude-4.4 earthquake shook 4km away from South Pasadena.

Within minutes from the quake that struck at around 12:20 p.m., earthquake-related incidents were reported in the city of Pasadena with one person being trapped inside an elevator and a water pipe bursting in front of city hall, according to Lisa Derderian, the public information officer for the city.

"The quake was felt strong in Pasadena here," Derderian said, adding it's first day of school for the Pasadena Unified School District. "(We're) hoping that teacher and school personnel are talk to them about what to do and aftershocks."

Shaking was felt across the Los Angeles region as well as northern Orange County, Robert De Groot from the U.S. Geological Survey said, adding the ShakeAlert early warning messages were sent out.

It was initially reported as magnitude-4.7 with the quake's depth being 9km.

The South Pasadena region has a population of more than 26,000.

The Los Angeles Police Department is urging people to be prepared for aftershocks.

This is a developing story.