"We didn't think anything of it until the tremor didn't stop," said Park, who is general manager of Japan operations for Appirio, a San Francisco-based .

"We saw other high-rise offices and apartments visibly shaking -- it was hard to stand without losing my balance," said Park, in an e-mail response to questions.

The building's elevators shut down, as did trains and subways. Half of his 30-member team walked home, making treks of five to 10 miles, while others waited for the trains to reopen.

Tokyo is about 150 miles away from earthquake's epicenter, and Park said there was minimal structural damage in the city. But certain portions of the Tokyo metro area experienced power outages.

From a communications standpoint, this is the situation Park said he faced: Cell networks weren't working, but land lines were; and 3G-based Web browsing was slower than usual, but worked.