Nearly 1,900 holders of Hawai'i commercial driver's licenses are being warned to take measures to prevent identity theft after a state computer containing personal information was stolen three weeks ago.

The state Department of Transportation sent a letter Monday to the affected commercial driver's license holders to notify them of the security breach. The laptop computer contained the names, addresses, Social Security numbers and other personal information of 1,892 commercial vehicle license drivers.

Statewide, there are about 30,000 people with commercial driver's licenses, said Tammy Mori, DOT spokeswoman.

The laptop was assigned to a DOT motor vehicle safety officer in charge of inspecting vehicles on O'ahu and was taken March 18 from a fifth-floor state office in the Kakuhihewa Building in Kapolei. The inspector said he left the computer unattended about 9:30 a.m. and that when he went back to get it a half-hour later it was gone, the DOT said.

The incident was reported to police, which opened a second-degree theft case. No arrest had been made as of yesterday.

Although the theft occurred on March 18, the state did not notify the affected drivers until Monday. Mori said the department needed to follow protocol before sending the letters.

"So we went through all of the proper procedures before we moved forward with this."

Brennon Morioka, DOT director, apologized for the incident and its "very serious impact the missing information could have on so many individuals." He said his office is working with police and the attorney general to ensure that protective measures are taken to protect the identities of the drivers involved.

Morioka said there have been no reports that the information has been used for illegal purposes.