VIDEO: A Sioux City man was arrested and charged after allegedly setting a fire inside the emergency room at UnityPoint Health-St. Luke's. Sioux City Police arrested David Warner, 34, of Sioux City, and charged him with criminal mischief and first degree arson. Court documents say that Warner was taken to UnityPoint, just after midnight, for a mental evaluation per his request. While in the exam room he had set a roll of toilet paper on fire in an exam room in the emergency department. When the sprinkler system turned on in the bathroom he damaged the sprinkler head causing a constant flow of water. Flooding occurred in the emergencyroom, the first floor hallway, the hallway to ambulance entrance and lower level kitchen.