YOKOTA AIR BASE, Japan — The Tokyo Metropolitan Government held its fourth annual earthquake disaster-preparedness drill Wednesday, using the flight line here as a staging area and relay base to transfer patients and equipment from fixed-wing aircraft to helicopters.

Tokyo Gov. Shintaro Ishihara observed the exercise alongside Col. Mark Schissler, the 374th Airlift Wing commander. Participants included the Japan Air Self-Defense Force, Tokyo Fire Department, Tokyo Metropolitan Police Department and the Japanese Red Cross.

Similar training sessions were conducted in Tokyo, including one at the Hardy Barracks helipad that simulated the transfer of an injured patient to a hospital.

The event coincides yearly with the anniversary of the 1923 Great Kanto Earthquake, a massive 8.3-magnitude temblor that killed more than 140,000 people, left hundreds of thousands homeless and devastated Tokyo and outlying communities.

“The objective of the exercise is to test the Tokyo Metropolitan Government’s ability to respond to a major earthquake,” said Capt. David Westover, a 374th Airlift Wing spokesman. “The annual exercise is an excellent example of the cooperation that exists between the Tokyo Metropolitan Government, the Japanese military and civil service organizations, and the U.S. military here at Yokota Air Base.”

Wednesday’s scenario involved a major earthquake striking northeast of Tokyo at about 6 a.m., Japanese government officials said.

Homes and businesses were severely damaged in Taito, Sumida and Arakawa wards, closing roads and railways and cutting off electricity, gas and water.

Death and injuries were also extensive under the simulation, Westover said, a result of massive fires and numerous destroyed buildings.

The Tokyo government used a portion of Yokota’s runway to stage the airlift of supplies from distant prefectures, as well as rescue personnel and vehicles. The base could also facilitate the transport of critically injured people from surrounding cities to better-equipped medical centers, officials said.

About 28,000 people took part in the drill within the Tokyo metropolitan area, including government and fire officials, volunteers and residents in eight prefectures and cities, according to a Tokyo Metropolitan Government news release.

At Hardy Barracks, about a dozen emergency and rescue personnel handled delivery of the patient, who landed in a helicopter with a doctor and nurse. The individual was then rushed to a local hospital by ambulance.

“The drill was conducted without any problems,” a Tokyo Metropolitan Government official said, adding that this marked the second time the helipad was used in the exercise.

With the annual simulation, officials aim “to improve the ability to respond to disasters by conducting relief effort drills with mutual coordination by Tokyo Metropolitan Government, Taito ward, Sumida ward and Arakawa ward and to establish self-help and assistance systems immediately after earthquake disaster,” the release stated.

Participants also hoped to strengthen communication in times of crisis by providing safety information to residents through technological improvements.

A different scenario is produced every year, a Tokyo Metropolitan Government spokesman said.