VIDEO: Firefighters were called Tuesday morning to a fully-involved barn fire in Maple Valley just off Highway 18. Just after 5:00 a.m., Puget Sound Fire said on Twitter that there had been a barn fire and that both the Valley Regional Fire Authority and King County Medic One were at the scene. They asked the public to avoid the area. A photo shared by PSF shows the barn engulfed by flames, and the entire exterior of the barn already destroyed by the fire. Authorities say the fire was extinguished in just over an hour. There were no animals in the barn at the time of the fire. There were no injuries to any firefighters, and the cause of the fire is currently under investigation.