MADISON, Wis. (AP)  -- A Northwest Airlines jetliner heading to Chicago made a safe emergency landing in Wisconsin on Monday after the pilot reported a pressurization problem, an airline spokesman said.

Flight 126 with 115 passengers was flying to O'Hare International Airport from Minneapolis when the incident took place about 10:30 a.m., Northwest spokesman Vin Parker said.

There was no danger to the passengers,'' he said. ``It was a computer alerting the pilots that there may be an issue.''

The plane was flying at 29,000 feet when the automatic pressurization system gave a reading for about 10,000 feet, he said.

``If the pressure is below 14,000 feet, the (oxygen) masks won't drop because it is not critical,'' Parker said. ``There was no breach in the aircraft. The system showed a loss of pressure. Whether that actually happened or not remains to be seen.''

The flight was diverted to Dane County Regional Airport as a precaution and no one was hurt, Parker said. The passengers were taken off the DC-9 and transferred to a bus for the rest of the trip to Chicago.