It happened slowly.

As news of Robert Mondavi’s passing spread through the valley Friday, the winery that bears his name canceled winery tours at 1 p.m. A half hour later, officials at the landmark Oakville winery closed the tasting room and set the winery’s three flags — the American flag, the California flag and the Italian flag — at half mast.

By 2 p.m. an employee set out cones at the entrance to the winery, alerting motorists that the winery was not open to the public.

Eric G. Morham, president of Icon Estates, which operates the Mondavi winery, said the winery will remain closed Saturday and Sunday out of respect for the Mondavi family. However, the grounds will remain open and people are welcome to come walk the grounds and pay their respects.

The winery will reopen Monday.

Morham said Mondavi’s death was unexpected and that Margrit Mondavi, his wife, was in London and would return to Napa Valley immediately.

“(Mondavi) had a vision that Napa Valley wines could stand in the company of the great wines of the world,” Morham said.

He said the family will hold a private service.

But in accordance with Mondavi's wishes, there will be “a big party” at the winery within weeks. A firm date has not been set. The memorial will be open to the public.

Even tourists who aren't immersed in Napa Valley culture understood the significance of Mondavi's death.

Deb Mertz of Connecticut said she was visiting Far Niente winery when she heard the news.

“I know he and his family are so important to the valley,” she said. “In reading some things to prepare to come here, it was obvious how much the family contributed to the area.”

Others, like Mike and Nicole Young of Las Vegas, were aware of Mondavi's reputation primarily through his wines. They said the quality of Mondavi's riesling inspired them to visit his winery.

Jim Silberman, visiting from New Jersey, learned of Mondavi’s death while at the winery.

“Our tour guide was telling us about the wines and mentioned this was one of Mr. Mondavi's favorites and he gets a tear in his eye, then later we heard he had died,” he said.

Ryan is interim city editor at the Register. Duarte is a staff writer for the St. Helena Star. Register Photo Editor J.L. Sousa contributed to this article.