During the course of a working fire in an eight story high rise, all radio communications were blocked due to a faulty radio. In this instance the incident was de-escalating however due to the nature of this if we had been operating in a more aggressive mode all companies may have been compromised. The Engine Co officer had been operating under a flowing sprinkler head which thankfully held the fire in check until the standpipe stretch was made. During this time he said that his radio had been soaked by the water flowing. It was at approximately the same time that no one was able to communicate via radio, the fire-ground radio channel we use sounded like there was an open mic. The Incident Commander was able to see who was calling him on the faceplate of his mobile radio in the Command vehicle but no voice was heard. The engine officer noticed that his radio was making buzzing and clicking sounds and he turned it off which then allowed all communication to begin again. This whole scenario lasted several minutes.
The very next day tour Fire Marshal and the LT. who handles radio maintenance began to look into the problem. The examined the suspect Radio and found no obvious visual defects. They then gave the radio a dousing with water and were able to replicate this scenario exactly. What we found- Our department is in a consolidated dispatching center with numerous cities. After being awarded a sizeable grant a few years ago, all radios for the cities were upgraded to a digital radio that operates on the MARCS system. When the equipment was purchased the lapel mics specified were not water resistant and not rated for firefighting use. Since the incident all lapel mics have been removed and are being replaced with water resistant firefighting rated mics. Fortunately this incident was past the initial stages and was de escalating when the failure occurred. Thankfully no one was hurt- this time