Amund Olsen family

Amund Olsen, son of Ole Johanssen and Anne Olsdtr., was born 14 Jan. 1837 at Skaarslien, Gausdal, Norway. Supposedly he married and had 6 children. It is said that he and his wife and two daughters drown while out sailing and that their other 4 children eventually came to State of Washington. 3 of those children were Iner, Carl & Thora. I'm looking for marriage date & place and to whom Amund married and for the birthdates and names of their children and if, possibly, if there would be an actual record of their drowning? Thank you, Dusty