reduced unemployment to 3.7% and inflation remained below 2%. With the economy booming Johnson began his "Great Society" which vastly expanded social programs. By the end of the decade under Nixon, the combined inflation and unemployment rate known as the misery index (economics) had exploded to nearly 10% with inflation at 6.2% and unemployment at 3.5% and by 1975 the misery index was almost 20%. Assassinations and attempts Prominent assassinations, targeted killings, and assassination attempts include: Disasters Natural: The 1960 Valdivia earthquake, also known as the Great Chilean earthquake, is to date the most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale. It caused localized tsunamis that severely battered the Chilean coast, with waves up to 25 meters (82 ft). The main tsunami raced across the Pacific Ocean and devastated Hilo, Hawaii. 1963 Skopje earthquake was a 6.1 moment magnitude earthquake which occurred in Skopje, SR Macedonia (present-day Republic of Macedonia) on 26 July 1963, which killed over 1,070 people, injured between 3,000 and 4,000 and left more than 200,000 people homeless. About 80% of the city was destroyed. 1963 – Vajont dam disaster – The Vajont dam flood in Italy was caused by a mountain sliding in the dam and causing a flood wave that killed approximately 2,000 people in the towns in its path. 1964 – The Good Friday earthquake, the most powerful earthquake recorded in the U.S. and North America, struck Alaska and killed 143 people. 1965 – Hurricane Betsy caused severe damage to the U.S. Gulf Coast, especially in the state of Louisiana. 1969 – The Cuyahoga River caught fire in Ohio. Fires had erupted on the river many times, including 22 June 1969, when a river fire captured the attention of Time magazine, which described the Cuyahoga as the river that "oozes rather than flows" and in which a person "does not drown but decays." This helped spur legislative action on water pollution control resulting in the Clean Water Act, Great Lakes Water Quality Agreement, and the creation of the federal Environmental Protection Agency. 1969 – Hurricane Camille hit the U.S. Gulf Coast at Category 5 Status. It peaked and made landfall with 175 mph (280 km/h) winds and caused $1.42 billion (1969 USD) in damages. Non-natural: On 16 December 1960, a United Airlines DC-8 and a Trans World Airlines Lockheed Constellation collided over New York City and crashed, killing 134 people.