went through the sunroof. >> we were trying to out run it and said let's go. and he said my head and was bleeding profusely. >> two other tourists did not escape from a separate rockfall. they were on an anniversary trip were caught in a fall on wednesday injured was killed and his wife judy is in critical condition. julie: what causes the slide? to make it is a combination of moisture and temperature is calling that - - causing barack to expand over time so the granite stars to peel off. so on average the park sees 80 falls per year but they are much smaller some visitors say they are feeling more cautious but they say they just keep on going.