One or more aspects relates to monitoring conditions under a raised floor in a data center. A grid of raised floor tiles has regular floor tiles interspersed with sensor floor tiles. The sensor floor tiles include: one or more sensors to monitor conditions under the raised floor; and one or more cameras to collect images of conditions under the raised floor. A sensor controller is used to locate a sensor tile with a sensor condition that is out-of-band from a reference condition band; and an image controller is used to locate an image difference corresponding to the out-of-band sensor condition.