Anyone who drives a car has noticed that gas prices are dramatically lower than they've been in years due to lower oil prices. While we're all happy that filling up our tanks is easier on the wallet, there is a down side: cheap oil can cause people who make a living in the oil industry to lose their jobs, and their homes to foreclosure.
When the price of oil plunges, companies in the oil business or businesses that service or support them, lay off some workers or pay them less. Those workers are more likely to be unable to afford their mortgages payments and fall into foreclosure. The oil business is employs a lot of people, so when it suffers, a lot of workers can suffer.