Sinkholes (a True Book: Extreme Earth)

Can you imagine watching as a busy street or even the floor of your house suddenly collapsed into a gaping pit? That is precisely what can happen when a sinkhole forms underground. Readers will find out how water can wear away at underground rock and cause it to weaken over time. They will also learn how human activities can increase the risk of sinkholes and how sinkholes are predicted and repaired.