Tacoma Narrows Bridge caused by aerodynamic flutter of the deck. Failure of dams was not infrequent during the Victorian era, such as the Dale Dyke dam failure in Sheffield, England in 1864, causing the Great Sheffield Flood, which killed at least 240 people. In 1889, the failure of the South Fork Dam on the Little Conemaugh River near Johnstown, Pennsylvania, produced the Johnstown Flood, which killed over 2,200. Other failures include balcony collapses, aerial walkway collapses such as the Hyatt Regency walkway collapse in Kansas City in 1981, and building collapses such as that of the World Trade Center in New York City in 2001 during the September 11 attacks. Power outage A power outage is an interruption of normal sources of electrical power. Short-term power outages (up to a few hours) are common and have minor adverse effect, since most businesses and health facilities are prepared to deal with them. Extended power outages, however, can disrupt personal and business activities as well as medical and rescue services, leading to business losses and medical emergencies. Extended loss of power can lead to civil disorder, as in the New York City blackout of 1977. Only very rarely do power outages escalate to disaster proportions, however, they often accompany other types of disasters, such as hurricanes and floods, which hampers relief efforts. Electromagnetic pulses and voltage spikes from whatever cause can also damage electricity infrastructure and electrical devices. Recent notable power outages include the 2005 Java–Bali Blackout which affected 100 million people, 2012 India blackouts which affected 600 million and the 2009 Brazil and Paraguay blackout which affected 60 million people. Fire Bush fires, forest fires, and mine fires are generally started by lightning, but also by human negligence or arson. They can burn thousands of square kilometers. If a fire intensifies enough to produce its own winds and "weather", it will form into a firestorm. A good example of a mine fire is the one near Centralia, Pennsylvania. Started in 1962, it ruined the town and continues to burn today. Some of the biggest city-related fires are The Great Chicago Fire, The Peshtigo Fire (both of 1871) and the Great Fire of London in 1666. Casualties resulting from fires, regardless of their source or initial cause, can be aggravated by inadequate emergency preparedness. Such hazards as a lack of accessible emergency exits, poorly marked escape routes, or improperly maintained fire extinguishers