Google said Monday it expected to restore all Gmail accounts after a bug in a storage software update wiped out the email messages of a small number of users of the free Internet service.

Google says an update to e-mail storage software led to an unexpected bug Sunday that left tens of thousands of Gmail users without access to their messages.

Google Inc. said in a blog post late Monday night that e-mails were never actually lost, and it has restored access to many people who were affected. says about 0.02 percent of users encountered the problem, or two out of 10,000. Gmail has hundreds of millions of users worldwide.

Google says it backs up users' information on tape. Since tapes are offline, they are protected from such bugs.

Google vice president of engineering and site reliability czar, Ben Treynor, says Google is "sorry again for the scare."

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