Twenty-eight years ago today, in the aftermath of a bungled Communist Party news conference that changed the course of history, as crowds of people from East and West Berlin traversed the wall that had kept them separated for decades — first by overwhelming the guards at border crossings and checkpoints, then by climbing atop the wall itself — Serge Schmemann, then The Times’s bureau chief in Germany, was seated in a hotel room in West Berlin, typing away on his computer, not yet privy to the magnitude of the events unfolding outside.

There came an unexpected knock on his door.

Victor Homola, who for years had worked with The Times as an East German interpreter, was standing outside the room. He had been among the first to cross the border, entering West Berlin for the first time in his life — and he was intent on tracking down Mr. Schmemann to relay the news.

“It’s over!” he remembers saying to Mr. Schmemann. “The wall has fallen. It’s over.”