NORTHRIDGE ( — Friday marked the 20th anniversary of the Northridge Earthquake that killed 57 people and injured thousands more.

The 6.7-magnitude tremor struck at 4:31 a.m. on Jan. 17, 1994 and caused more than $40 billion in damage. It was the costliest natural disaster in U.S. history.

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The quake affected an area spanning Ventura, Los Angeles and Orange counties, or 2,192 square miles.

Officials said more than 20,000 people were left homeless. An estimated 40,000 homes were damaged or destroyed, some as far as 85 miles away from the epicenter.

Several events will be held Friday across the city to commemorate the quake.

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Councilmember Mitch Englander will hold a 6 a.m. event at the Northridge Recreation Center  to  recognize local community heroes and remember the lives impacted by earthquake.

The Valley Economic Alliance will hold a daylong event at Cal State Northridge featuring quake-related workshops.

A lunch will also honor those who played a critical role in the Southland’s recovery effort, including  former Councilman Hal Bernson, former Mayor Richard Riordan and then-Gov. Pete Wilson.

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