Complex sentence: Approaching a hill they run into a hailstorm, Jo drives ahead of the chasers to intercept the oncoming tornado, and a telephone pole falls on the back of Bill's truck and knocks DOROTHY II out onto the road, disabling it.
Split into simpler sentences: Approaching a hill they run into a hailstorm, and Jo drives ahead of the chasers to intercept the oncoming tornado. A telephone pole falls on the back of Bill's truck and knocks DOROTHY II out onto the road, disabling it.