josie sturman, abc 2 news. >>> 4:48. now a medical mystery. more than a dozen students in one high school coming down with something change. they're all twitching uncontrollably. abc 2 news health reporter linda stow is here to tell us the cause remains unclear. linda. reporter: well, charley, the cause is unclear, but we've learned the school district that's affected has its own natural gas wells. they supply the school with fuel and the wells use a controversial technique called fracking that shoots a chemical mixture into the earth to force out gas. the question now is is the gas from the wells contaminating the water, soil or air. 15 students have come down with similar tick-like symptoms. it's happening at a high school in upstate new york in the leroy school district. lana clark says her daughter lauren has been suffering since october. doctors have somethinged some of the students with conversion disorder, a stress-based condition. but many in the community fear there may be something in the environment and parents say school officials