We have a trailer that has a maze with multiple levels, stairs, movable walls, simulated wires and rafters.  We use this to practice search and rescue in a structure fire.  We can fog this trailer up to simulate a fire with a fog machine.
This is what the firefighters trained on during one of two trainings in May.  They practiced searching for persons and communication with each other.  A structure fire is a loud environment and team member communication is important to practice.