Auto makers in Japan are assessing damage to their operations following the nation’s worst earthquake in more than a century.

The massive tremor, which measured 8.9 on the Richter scale, has forced Nissan to shut down its plants and close its global headquarters in Yokohama for the weekend. Work may resume Monday, depending on the state of the supply base.

Among affected plants is the auto maker’s site in Oppama, sole source of the Nissan Leaf electric car.

The quake triggered a small fire at Nissan’s Togichi plant, but it has been extinguished. The auto maker also reports two Tochigi employees suffered minor injuries.

“The company has advised employees to remain inside facilities where it is safe,” a Nissan statement says. “However, those who are able to walk home are allowed to leave their offices based on their personal discretion.”

Nissan says it lost power at its Atsugi City tech center in Kanagawa prefecture. Employees there have been evacuated to the nearby Nissan Advanced Technology Center.

A Honda North America spokesman says the auto maker still is gathering information on possible damage or shutdowns at its Japanese plants.

News reports from Japan say one worker was killed when a wall collapsed at Honda’s Tochigi research-and-development center. About 30 workers were injured.

Despite reports Toyota had shut down at least two assembly plants and a parts factory, a New York-based spokeswoman for the auto maker tells Ward’s the company is up and running at all locations.

Mira Sleilati says she is unaware of any injuries to Toyota employees, adding the auto maker has established an emergency task force to assess the situation.

Some dealers in northern Japan, site of the quake’s epicenter, have reported damage, she adds.

cschweinsberg@wardsauto.com