The Mira Vista Country Club in El Cerrito was near the epicenter on the Hayward Fault.
"About 5:30 everything just started to shake a little bit at first and then a little bit more. After a little bit of a pause it then really shook the building pretty good," said Golf Course Superintendent Tim Youngberg.
The staff of the Mira Vista Country Club was in a meeting when the quake hit. The Hayward Fault runs right through their property, underneath a fairway, so they knew they needed to head out immediately and look for problems.
"I haven't seen any damage yet. I had a few guys go around the course and around the building to check to make sure there isn't any irrigation breaks, or anything wrong with the building and everything seems to be good so far," said Youngberg.
The buildings here are almost 100 years old, but the chimneys are still standing - they couldn't find any damage. The USGS placed a shake monitor at the club to take readings from this fault line. The big shock this morning was what the monitor found.
"It was a pretty good jolt and then to find out it was only a 4.0 - that was kind of surprising; I thought it was bigger," said Youngberg.
The neighborhood next to the country club and the fault was jolted awake this morning, but everyone and everything appeared OK.
"I felt an initial pop and I heard a roar behind the pop and then my house started to shake. I walked around my house to see if there was damage -- in fact there was none," said Bill Saner of El Cerrito.
"I just kind of jumped out of bed - then made sure everything was OK, the family was OK," said Dean Kaneshiro of El Cerrito.
Residents saw each other's lights turning on just after the quake and the texts and emails started flying.
"Your heart rate increases when you get one of these tumblers, and this was more pronounced, a little more aggressive than others we've had in the Bay Area," said Saner.
El Cerrito police dispatch said they have not had to respond to any earthquake related calls.