The first movement indication occurred on Friday, August 17, 1956. Cracking occurred in the foundation of a recently built structure. The cracks were repaired, but new cracking occurred just days later. Ten days after the first indication of movement, cracking propagated to Palos Verdes Drive South. By September 4, an offset of 4 inches (10 cm) was observed on the road. By mid-September, more pronounced cracking was observed. Distortion became noticeable on the Portuguese Bend pier on October 4 of that year. A survey station was installed to monitor ground movement. The station recorded movement of 3 to 4 inches (≈7 to 10 cm) per day. By the end of October, movement slowed to ≈¾ inch (2 cm) per day. The amount it moves is unknown today. Drilling projects over the next several months determined the location of the slip surface, and the location of standing groundwater.