On August 21, 2019 @ 16:47 hrs, Units were dispatched for a commercial building fire ITA of 5000 Block of Potomac DR. Reports were the hot water tank caught fire. TR28, E2, & BATT28 were first on the scene with nothing evident and the building evacuated. BATT28 established command and Interior crews reported no smoke or fire found. The hot water heater was located and had sparked - Power was secured. Property owner will call electrician to make the needed repairs. Fire/Rescue inservice.