According to the United States Geological Survey (USGS), a magnitude 5.1 earthquake struck northeastern New York State, approximately 15 miles southwest of Plattsburgh, New York, on Saturday, April 20, 2002, at 6:50 a.m. EDT. The moderate earthquake was felt in Buffalo, New York, and as far away as Cleveland Ohio; Portland, Maine; and Baltimore, Maryland due to the hard bedrock found in the northeast.

Damage was minimal and Plattsburgh media reported that two chimneys had fallen and that some windows had broken in various residences. Additionally, a church in Au Sable Forks very near the earthquake's epicenter, was reported to have experienced some limited cracking.

According to Kevin Murphy, Director of Public Works for the City of Plattsburgh, no structural or nonstructural damage was observed in any city bridges, roads, underground facilities or city owned buildings. Public Works crews had been out inspecting damage since the earthquake occurred.

Scott Docteur, an engineer for the New York State Department of Transportation (NYSDOT) told MCEER that one piece of state route 9N had been damaged but remained open for single lane traffic. The small segment of road collapsed when the soil embankment below it shifted out from underneath. Docteur also said that the NYSDOT closed one bridge on the South Junction Road just south of Plattsburgh for further inspection. MCEER learned that the bridge had been reopened early Sunday morning.