The U.S. Navy’s huge Naval Air Weapon Station in California was closed after one of the largest earthquakes to hit Southern California since the early ’90s.

According to the U.S. Navy, Naval Air Weapons Station China Lake, located in the Western Mojave Desert region of California (approximately 150 miles north of Los Angeles) was closed Friday as officials assessed infrastructure damage caused by a 6.4 magnitude earthquake shook southern California on Thursday.

“The United States Geological Survey has confirmed that the epicenter of the series of recent, local quakes was on two faults that are located aboard Naval Air Weapons Station China Lake,” stated a post on the base’s Facebook page. “There is currently a team from [the U.S. Geological Survey] and California Geological Survey on the installation studying the event.”

At this time, NAWS China Lake continues to assess infrastructure damage; with no casualties or injures reported.

The only authorized access to NAWS China Lake continues to be Mission Essential Personnel (as identified in the MEP program) and Installation housing residents and this restriction will continue through 5 a.m. Monday, July 8.

Mission Essential personnel should continue to use caution when accessing buildings.

China Lake is the United States Navy’s largest single landholding, representing 85% of the Navy’s land for weapons and armaments research, development, acquisition, testing and evaluation use and 38% of the Navy’s land holdings worldwide. In total, its two ranges and main site cover more than 1,100,000 acres, an area larger than the state of Rhode Island. The roughly $3 billion infrastructure of the installation consists of 2,132 buildings and facilities, 329 miles of paved roads, and 1,801 miles of unpaved roads.