The U.S. securities industry canceled equity trading on all markets today, moving to protect workers as Hurricane Sandy barreled toward New York City with 70-mile-per-hour winds and the threat of an 11-foot sea surge.

The shutdown, announced by the Securities and Exchange Commission, may extend through tomorrow and followed an earlier decision by the New York Stock Exchange to close floor trading. Risks posed by the storm, expected to come ashore late today in southern New Jersey and potentially affect 60 million people, were deemed too great to require workers to travel.

"It was a judgment decision based on the safety of a lot of market participants, especially as the storm seems to be getting more severe," said Larry Leibowitz, chief operating officer of NYSE Euronext, in a phone interview. "Given all the emphasis on stability and investor confidence, operating the market that way didn't seem to serve the public interest. Why do this? To prove we can? That didn't seem to make a lot of sense."