In the event of a major earthquake, a city may have a lot more to worry about besides just collapsing buildings. City dwellers depend upon pipelines for water to drink and energy to heat and light their homes. Those buried conduits are vulnerable to the ground waves of a quake's force. In the central U.S., the petroleum pipelines are relatively recent, and able to better withstand quakes; they face more danger from the soil liquefaction and landslides that quakes sometimes trigger. In the East, energy pipelines and water systems are older and made of more brittle materials that pose a much greater risk of failure.