The 27-year-old woman died of smoke inhalation.
Fire Marshal Heidi Scarpelli told The Columbian the woman had been smoking in bed Sunday morning.
Residents who saw smoke at the second-floor apartment banged on the door and then forced their way inside. They rescued a dog before they were forced out by thick smoke.
Firefighters contained the fire to one unit at the Courtyard Village Apartments in Vancouver's Rose Village neighborhood. Property damage is estimated at $42,000.