M 4.3 near Kokopo, Papua New Guinea

What to do during a mainshock

Shaking can cause falling objects, collapsing structures, and downed power lines.

• Drop, Cover, and Hold On. Get under a sturdy table or next to an interior wall; protect your head and neck.
• Stay indoors until the shaking stops and you are sure it is safe to exit.
• If outdoors, move to an open area away from buildings, power lines, and trees.
• If driving, pull over in a clear area and stay in the vehicle.
• After the shaking, watch for aftershocks and check for injuries, gas leaks, and structural damage before moving through the building.

General guidance based on NWS, FEMA, and Ready.gov. Always follow instructions from local officials, which take precedence.