For both at La Conchita, California and at Oso, Washington, which of the following is true?
1) study of each area before the landslide reveals evidence of former landslide activity
2) study of each area before the landslide shows no sign of former landslide activity
3) the landslides were unpredictable
4) preventative measures were very successful at thwarting landsliding
5) no deaths occurred in later events because people were warned of the danger