SACRAMENTO (CBS SF) – A Southwest Airlines flight from Sacramento to Denver was diverted to Oakland International Airport Sunday evening because of a pressurization issue, a Southwest spokesman said.

Flight 1665 from Sacramento International Airport landed safely in Oakland at about 5:15 p.m., airport spokeswoman Keonnis Taylor said.

The flight had 133 passengers on board.

Southwest Airlines officials had a new aircraft waiting for the passengers to take them to Denver.

The passengers will get to Denver about three hours behind schedule, Southwest Airlines spokesman Dan Landson said.

The aircraft that left Sacramento will stay out of service until it is checked.