About 6:30 am an 18-wheeler was northbound on FM 1725 just past FM 3081 (Dabny Bottom Road) when he ran off the road in a curve and rolled over. The truck was carrying 2800 gallons of Sodium Dioxide. When it crashed the tank broke at the seam releasing close to 1300 gallons both as liquid and vapor. The remaining 1500 gallons remain in the tank but is still gassing. A school bus with 29 onboard drove through the cloud just after it happened. All students and the driver were transported to HCA Conroe where they were treated and released. A woman who also drove through the scene made it to Cleveland when she summoned EMS due to breathing issues. A rental company driver stopped at the scene to assist and was also affected. Two Montgomery County Deputies who were assisting in the evacuation were also affected and went to HCA Conroe to be evaluated. At 3pm the scene remains. HAZMAT crews say it could be well into the evening. Tankers from Montgomery, Caney Creek, North Montgomery County, New Waverly, and Cleveland were summoned to the scene, Montgomery County Office of Emergency Management responded with the command truck as did the South County Fire Department. Porter Fire responded with a DECON unit for affected personnel and great. Woodlands, Harris County, Conroe and Walker County HAZMAT are also on the scene. The truck driver is deceased. Many residents say FM 1725 is heavily traveled by trucks in order to avoid the weigh station in New Waverly on I-45. We will keep you updated through the night.