Toolbox Murders (2004)

In Hollywood, the young teacher Nell and her husband, the resident Steven Barrows, move to an old building called Lusman Arms. Some sixty years ago, the place was glamorous, but presently is completely decadent. Many dwellers have disappeared along the years. While her husband is working in the hospital, the lonely Nell hears some weird noises and becomes afraid of the place. While jogging, she is introduced to (and becomes close to) her neighbor Julia Cunningham, and they schedule a hike together on the next day. Julia never shows up, and Nell looks for her in the building, finding a hiding block behind the wall, where an evil being, which was born from death, lives with many dead bodies.