PORTSMOUTH, Va. (WAVY) — Naval Medical Center Portsmouth is expected to hold a mass casualty drill on Thursday morning.

The training exercise will be from 5 a.m. to 7 a.m. outside its emergency department.

The Navy says the drill involves an ambulance and a minimal number of staff and actors that will be visible to patients.

“The drill will be conducted in a manner to minimize impact on patient care or operations in the emergency department,” a Navy spokesperson said.

It’s all about maintaining readiness at the U.S. military’s oldest, continuously operating military hospital. The facility was recently named a Level II trauma center, meaning it can now take in local trauma patients who are not in the military.