An earthquake measuring 6.9 struck Monday in Mexico but people in San Diego's downtown high rises felt the shaking.
Civil protection officials in the two states on either side of the quake -- Baja California and Sonora -- said there were no reports of damage or injury.
The quake came minutes after two others calculated at magnitudes 5.8 and 5.0, according to the earthquake center.
In San Diego one city employee reported seeing crowds of people filing out of her building. By 11:30 a.m., the crowd of people had moved back inside.
It was more of a strange sound than a rattling according to one downtown worker.
“Wasn’t so much that I felt it but I heard it,” said Greg Shimansky. “It lasted so long it didn’t feel so much like an earthquake.”
Charles Washington was sitting at his desk in a building downtown. “It felt like a creaking noise. It lasted up to 40 seconds,” said Washington. “We thought it was a window washer at first too.”
“We thought it was really something,” he said.
The quakes were all centered in the middle of the narrow slice of sea between the Baja peninsula and Mexico's mainland, which should help cut down on its chances of causing major damage, said Don Blakeman, an analyst at the center.
"It's going to be felt extremely widely and it's possible there may be some damage but there's no way to speculate at this point," Blakeman said.
NBCSanDiego received reports from two people working on higher floors at two separate downtown high rises saying books fell of shelves and file cabinets rocked.
One of our Facebook users, Raffael Antonio Scullari in North Park, messaged us saying nothing was felt in North Park.
Delfina sent us an email saying the SANDAG offices at the Wells Fargo Plaza were swaying. Daphanie works for the city at 4th and B and emailed us to tell us that her building shook during the quake as well.
Did you feel the shaking? Let us know about your experience in the comment field below.
Check back for more information on this developing story.