OVFC dispatched at 0558 hours for unknown MVA involving a work truck with 100lb propane cylinder aboard. First arriving 2585, discovered a rollover accident on a steep hill with an active propane tank venting in the woods, and two victims injured. Further units arrived on scene, deployed a handline for protection and mitigated the propane hazard. 2585 transported one patient ALS to AMCH. Units on scene; 25-01, 25-02, 25-03, 25-05, 25-07, 25-09, 25-30, 25-31, 25-32, 25-85, 55-05, 55-92.