Read the excerpt from "the great molasses flood of 1919."

it had been cracked for years. it had even leaked many times. the owners did nothing about the cracked and leaky tank. in the cold winter weather, the cracks got bigger and more dangerous.
the cause-and-effect structure describes the
hazards of ignoring a problem.
process of fixing a leak.
reasons to avoid cold weather.
difficulty of detecting cracks.