Blue Book Article 9.05.010
In the Northridge Earthquake (January 17, 1994) eight major parking structures suffered partial or total collapse (NISTIR) and at least twenty others were heavily damaged. Most of these structures were relatively modern, having been constructed in the past 25 years prior to the Northridge earthquake. They ranged in height between one and eight stories, and were constructed of cast-in-place, precast concrete, or a combination of the two systems. The lateral force resisting systems included both cast-in-place or topped precast diaphragms with either concrete or masonry shear walls or concrete moment frames.