After an earthquake shook the East Coast on Tuesday afternoon, two nuclear reactors in Virginia have been taken offline.

The North Anna Power Station in Louisa County, operated by Dominion Resources, lost power after the 5.9 magnitude quake hit around 2 p.m. EDT. The reactors are operating safely on back-up power run by diesel generators, a Dominion spokesperson told the Associated Press.

Four generators are powering import safety equipment that keeps spent fuel cool.

“When something like this happen, everyone has to remember, more than half of the states in the U.S. are considered earthquake country, the Nation Review Online reports.

Remember what to do in the case of a seismic event. Duck, get under something sturdy like a desk or a doorway, get away from falling glass. Make sure that you are not in the way of falling objects like pictures, bookshelves, books, anything that’s not firmly connected to the wall.”

Dominion Resources shares fell to an intraday low of $47.76 from a high of $49.32, before recently changing hands at $48.80.

The energy company is headquartered in Richmond, Virginia. It is traded publicly on the NYSE.

The earthquake was felt as far north as Boston. According to New York Daily News, Governor Andrew Cuomo said no damage was done to the Indian Point nuclear power plant.