ALBUQUERQUE, N.M. (KRQE) – Fire investigators are looking into what caused a downtown Albuquerque warehouse to go up in flames. It's not the first time firefighters have been called to the vacant building. "This is a building that we are familiar with, it's a warehouse that's burned multiple times," says Lieutenant Jason Fejer with Albuquerque Fire Rescue (AFR). They say the report came in around 7:00 a.m. Saturday, of the fire on Sixth Street, just south of I-40. AFR rescues person from northeast house fire The department says firefighters quickly got the situation under control but the type of structure, along with the severe damage, made it a major undertaking to get the fire completely out. "So when we have crews in the interior of a building like this, it's really just managing some of those risks, being able to access the fire, and staying away from some of those areas that have already collapsed...and some of the holes we've already cut in the floor from previous fires," Lt. Fejer says. "These are dangerous operations. They're challenging, but we have to get in there and put them out." AFR is investigating the cause of that fire.