nancy o'malley is the alameda county district attorney. >> the range of charges could be murder all the way to involuntary manslaughter, and until we know what the evidence shows us, there may be other charges if the evidence presents that. >> reporter: 75% of the building has now been searched. for the last 48 hours, recovery workers have used buckets to separate personal possessions and building materials from human remains. no one knows exactly how many people were inside the space during the fire. the warehouse known as "the ghost ship" was two stories tall. there were no sprinklers or fire alarms. the upper floor contained a floor and event space. two sets of rickety stairs led to a bottom level, makeshift living spaces. >> that place is a deathtrap. >> reporter: shelly mack says she rented a trailer for a few months in 2014. she called police at least three times to report dangerous conditions.