Calaveras Fault 6.5 that occurred in 1911 in the Morgan Hill area. The most recent of these was a magnitude 6.2 earthquake near Morgan Hill in 1984. A magnitude 5.6 earthquake occurred on the Calaveras Fault on October 30, 2007 at 20:04 PDT (October 31, at 03:04 UTC), near Alum Rock. Prior to the 2014 South Napa earthquake, it was the most powerful quake to hit the Bay Area since the Loma Prieta earthquake of 1989, and the largest on the Calaveras Fault since 1984. Although it has been known for some time that the Calaveras and Hayward faults merge in the
1989 Loma Prieta earthquake than half of the more than 62,000 fans had reached their seats by the time of the quake, and the load on the structure of the stadium was lower than maximum. There had also been a seismic-strengthening project previously completed on the upper deck concrete windscreen that may have prevented large numbers of injuries in the event of serious damage or even a catastrophic collapse. Fans reported that the stadium moved in an articulated manner as the earthquake wave passed through it, that the light standards swayed by many feet, and that the concrete upper deck windscreen moved in a