Crews responded to a box truck explosion at Sierra Sid's Casino in Sparks early Wednesday morning. Authorities say the explosion was caused by improper packing of material in a 55-gallon drum. No further damage or injuries were reported. The Triad Hazmat Team, consisting of the Reno Fire Department, the Sparks Fire Department and Truckee Meadows Fire & Rescue (TMFR), responded to the explosion.