Police suspect someone spiked drinks at the house during a party Friday night, but they're unsure what it was and who was responsible.
According to police and a hospital nursing supervisor, all 12 had been released from area hospitals by Sunday.
Cle Elum Police Chief Scott Ferguson says his department is planning to meet Monday with other police agencies to coordinate interviews with everyone in the house. They're also waiting for toxicology tests.
Ferguson says many partygoers fled when officers arrived late Friday. Others were found unconscious or semiconscious throughout the house. Some hid. He says some who were sober tried to help others by putting them on beds or couches, but no one called for help.
Most of those at the party in Roslyn were students at Central Washington University.