Naval Hospital in Japan Tests Readiness During Mass Casualty Drill

Navy Medicine Readiness and Training Command Yokosuka, Japan, conducted a large-scale mass casualty drill Sept. 23, testing its ability to triage, treat and transport multiple simulated patients during a crisis.

The exercise included 10 simulated casualties, ranging from a femur fracture with controlled bleeding to complex scenarios such as punctured lungs, cardiac emergencies and burn injuries. Throughout the day, patients were received, stabilized and transferred, with the final casualty requiring medical evacuation through Naval Air Facility Atsugi.

In the culminating scenario, medical personnel from Navy Medicine Readiness and Training Unit Sasebo transferred a simulated casualty to Nagasaki Airport, where it was met by a C-12 Huron aircraft assigned to NAF Atsugi and a medical crew from NMRTC Yokosuka. The aircraft flew to Atsugi, where the patient was offloaded and transported by ambulance to Naval Hospital Yokosuka for further treatment.

“This drill gave us the opportunity to test not only our in-hospital care but also our coordination with outside commands, such as Fleet Air Western Pacific, to ensure rapid evacuation when needed,” said Nikolai Kerry, emergency manager at NMRTC Yokosuka.

Navy Capt. Torrin Velazquez, commanding officer of NMRTC Yokosuka, emphasized the importance of integrating new patient transport and aviation evacuation procedures into the command’s training cycle.

“Testing these new capabilities is essential to building the kind of muscle memory that ensures our teams can respond instinctively when seconds matter,” Velazquez said. “By practicing these processes until they come naturally, we strengthen our readiness and safeguard the lives of those who depend on us. I want to thank every sailor, civilian and partner command who played a role in making this exercise successful.”

Mass casualty drills are designed to prepare medical providers, first responders and supporting personnel for large-scale incidents such as natural disasters, terrorist attacks or major accidents. These events test readiness by requiring participants to triage patients, allocate limited resources and coordinate across commands in time-sensitive situations.

“While the scenarios are simulated, the pressure is real,” Kerry said. “These drills highlight gaps in our procedures, strengthen teamwork across agencies, and most importantly, help us save lives when an actual emergency happens.”

The exercise featured realistic injuries on a timed schedule to challenge hospital personnel. Early scenarios focused on orthopedic trauma, such as wrist and ankle fractures, while later patients presented more medically complex cases, including pregnancy issues and cardiac conditions.

Drills like this benefit both the Navy and the broader community by improving readiness, refining processes and ensuring all personnel know their roles in a crisis. NMRTC Yokosuka conducts mass casualty drills at least once or twice a year, often in partnership with other Navy installations and commands.

“This kind of training goes beyond the hospital walls,” Kerry said. “By practicing in different environments and with different partners, we ensure we’re prepared for anything — from a disaster on base to a real-world emergency at sea.”

The day concluded with the successful execution of the simulated casualty transfer from Sasebo to Yokosuka, underscoring the importance of interoperability and rapid response across Navy medical facilities in Japan.