BUTLER, N.J. (CBSNewYork) — Many people said they heard a loud boom and could feel their homes shake. Some even said they smelled burning afterward.

“I heard a loud boom and I’m on the other side of the highway,” Lori Milone wrote on Facebook.

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“Shook our house and then we detected a burning smell for a little while,” wrote Mark Selz.

“Double shakes here off Cascade Way, sounded like someone was in my house,” wrote Carrie Shaver. “What happened?” 

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“Me and my husband were watching TV and he said, “What was that?” It sounded like an explosion,” one Butler woman told WCBS 880’s Sean Adams. “We just went about our business. We didn’t hear anything else. He said to me, “You know, that almost made the house shake.”

CBS2’s Lonnie Quinn explained that low-magnitude earthquakes happen often in the Morris County area, as it – and Butler specifically – sit on the Ramapo Fault Line – one of the major fault lines in the U.S.

Quinn reported the reason the earthquake was felt by so many people in the area was that it was very shallow – occurring only about a mile to a mile and a half underground.

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By contrast, the 1994 Northridge earthquake in Los Angeles was 11 miles deep.