Ground Herement News Today

His debate-team coach. do we know why yet? >> reporter: there apparently, cri cristi, was a disagreement between the two. and the reason he came heavily armed with a shotgun and two molotov cocktails. at this point, they dont know why he shot the 15-year-old girl, an innocent bystander. >> schools going on lockdown, and i dont know why. the north side of the school, a fire in the library. >> reporter: chaos and confusion at colorados arapahoe high school as a gunman opens fire. >> im on the nort...