ABC7 Eyewitness News Team Coverage:
- Video: As it happened: 5.4 quake hits
- Video: Quake reactions: 'Oh my gosh!'
- Video: ABC7's "Shake Room"
- Granda: Shocked reactions in Pomona
- Powell: Caltech analysis of quake
- North: Does quake relieve pressure?
- M. Hernandez: L.A. City Hall shaken
- Frere: Minor damage in Anaheim Hills
- Garcia: Businesses react in Pasadena
- Lara: Macy's in Woodland Hills shut down
For more information on Tuesday's earthquake:
- Slideshow: Damage from quake
- Damage report: Latest on quake damage
- Reaction: abc7.com user comments
- Reaction: Mayor Antonio Villaraigosa
- Ready SoCal: Get your disaster preparedness bag
The quake wasn't the "Big One" scientists have long feared -- but it was strong enough to rattle nerves and get people talking again about emergency plans.
The quake was initially estimated at 5.8, but was downgraded to a magnitude-5.4 by the U.S. Geological Survey. A magnitude-3.8 aftershock hit ten minutes after the quake and more than 80 smaller ones followed, according to USGS seismologist Kate Hutton from Caltech. The last aftershock felt was a 2.7 that hit around 10:30 p.m. Tuesday.
Seismologists at Caltech have been busy analyzing computer-generated information about Tuesday's quake. They are still trying to identify the exact fault that ruptured causing the quake. Scientists say it occurred halfway between the Whittier and Chino faults, and it may have been on a fault line that was previously unknown.
"Well there's a couple possibilities in terms of the fault," said Hutton. "We need to have a located distribution of aftershocks because the aftershocks outline the section of the fault, the patch of the fault that broke during the main shock. And once we see that, we'll be able to choose between the options that we have."
Geophysicist Randy Baldwin, who is based at the National Earthquake Information Center in Colorado, says the quake hit in the area of the Whittier fault, an area that had a magnitude-5.9 shaker in 1987.
"It is in the area of the Whittier Fault, but there are quite a number of faults criss-crossing and going in different directions there," Baldwin said. "It's a geologically active area."
Caltech officials say the heaviest shaking happened northwest of the epicenter in the suburban Diamond Bar area. However, the quake was reportedly felt as far east as Las Vegas and as far south as Tijuana. Buildings swayed in downtown Los Angeles and San Diego for several seconds, triggering some precautionary evacuations.
The temblor started at a depth of about nine miles near Chino Hills. This is considered shallow, which may explain why many people felt such strong shaking.
Experts say as the hours pass it's less likely that the moderate quake will be followed by a big one.
"By the time we get 24 hours out from the earthquake, the chance of a precursor is down to one percent," said Hutton. "So the biggest risk is in the first day. It's actually during the first hours."
Minor structural damage was reported throughout Los Angeles, along with five minor injuries and people stuck in elevators, said City Councilwoman Wendy Greuel, serving as acting mayor. There are no reports of any major injuries or damage in Los Angeles, San Bernardino, and San Diego counties.
Security cameras captured the moment the earthquake hit at a bicycle store in San Dimas. Items hanging from the ceiling and the walls shook violently as people are seen running out for the store. Surveillance video from another store shows racks falling like dominoes.
"Yeah, I felt it and I jumped up and said 'aaahhh,'" said Pomona resident Linda Kay. "I mean, what do you do, you know."
"Quite a bit of shaking, quite a bit," said Rialto resident Rodney Burgess. "I wasn't here at the particular time, I live in the city of Rialto, but there in Rialto it jolted pretty good."
Pomona City Hall reopened Wednesday morning after a massive window shattered and fell during the shaking and the building was evacuated. There were also reports of glass breaking and items falling from shelves at various locations in the Pomona area, although none of the incidents were serious. A few buildings in the city were damaged, including an older brick building on Park Avenue where a wall collapsed, leaving a pile of rubble. People came by the building Wednesday to see the damage and take some pictures.
"If you look inside, I mean, I looked up and said 'man it's only going to be a matter of time that this thing is going to go down,'" said Burgess.
The strongest quake in a decade sent people running and sent items flying off shelves. Officials inspected airports, freeways and buildings, but so far there is little damage.
A Wal-Mart store was evacuated and the Fire Department was called in to make sure there was no gas leak or any structural damage. A sprinkler line snapped at a hockey rink in Corona, pouring water onto the ice.
Flooding occurred on three floors of a Macy's store in Woodland Hills after two pipes burst as a result of the quake. A water main break near Cal State L.A. lifted the roadway, prompting authorities to block off a section of the street near City Terrace Drive and Eastern Avenue in the City Terrace area for hours.
Even though there was only minor damage, there were a lot of rattled nerves following the quake.
"I thought, you know, every building in Pomona, you know, was coming down," said Mitch Politi. "And, you know, being in a situation like this you don't know what to think. You're just thinking, you know, the world's ending."
"It didn't seem like it would ever end," said Adriana Garcia. "It was the longest earthquake that I can say I felt."
The quake was a wakeup call for all Southern California residents to get earthquake kits ready and to be prepared because experts say the "Big One" is going to hit in Southern California sooner or later.
An earthquake drill called 'The Great Southern California ShakeOut' is planned for November. The event is designed to help individuals, businesses, and families get ready for a big earthquake.