Ontario Premier Dalton McGuinty had a close call on a Thursday night flight home from California when a problem with the plane's air conditioning caused those inside to lose oxygen.

The Air Canada pilot quickly maneuvered the plane from about 9 kilometres in the air to about 3 kilometres up, making it easier for passengers to breathe. The flight eventually made an emergency landing in Las Vegas.

"The plane came down very quickly," said a haggard-looking Dalton McGuinty on Friday. "It was an adventure. All's well that ends well, as they say... (The crew was) very professional."

Following the cabin seal burst, passengers heard a loud pop and saw members of the flight crew wearing oxygen masks. Some of the passengers were vomiting, others felt faint and everyone seemed very afraid, members of the premier's staff told CTV Toronto.

One staffer told CTV Toronto he tried to call his wife during the ordeal but the phones were not working.

The 136 passengers on the Airbus A-320 also included McGuinty's Ontario Provincial Police security detail.

The plane circled Las Vegas for three hours before being allowed to make an emergency landing.

It was a particularly notable evening for McGuinty, who chanced upon tennis star Andre Agassi while waiting in the Las Vegas airport. They had time for a quick chat before the premier boarded his flight the rest of the way to Toronto.

McGuinty didn't get home until 6 a.m., and had reportedly only slept for four of the 48 hours preceding the Friday morning ceremony where his new cabinet was sworn in.

McGuinty and his staff had been in California for a one-day trade mission.

With a report from CTV's Paul Bliss