The slide happened early Wednesday morning at Curry Village, a lodging and retail area. Erik Skindrud is a park spokesman.
"It woke everyone up. It got their attention big time."
About 180 truck loads of granite chunks crashed down to the Yosemite Valley floor…destroying seven cabins. The three injured people only had minor scrapes.
Skindrud says rock slides are not that unusual at Yosemite.
"Some of our experts think that they tend to happen when we have precipitation."
And it rained there last weekend…though not that much. Skindrud says rock slides can also be caused by geological faults in place for millions of years.
"…and it’s one of the natural processes that have actually created Yosemite Valley. So this is something ongoing and it’s a natural process and we can cope with it."
There was another, smaller rock slide in Curry Village on Tuesday. The area is off limits to the public for now. Park officials say they’re monitoring the area and will make a decision on when to let people back in.