An incident occurred on a Delta Airlines flight from Salt Lake City to Portland.
The plane climbed to 10,000 feet, at which point pressurization problems developed.
The Boeing was carrying 140 passengers to Portland when the plane failed to pressurize and the oxygen masks failed to deploy, the New York Post reports.
Passengers on board the plane reported their sensations. Some of them clutched their ears, feeling a sharp pain. Others complained of nosebleeds.
No serious injuries were reported, but at least 10 people required medical attention.
The Delta crew followed procedures and turned the plane around to return to Salt Lake City.
At the airport, specialists were waiting for passengers to provide emergency assistance.
Delta technicians fixed the plane's pressurization issue and returned it to service the next day.
The US Federal Aviation Administration announced that it had launched an investigation into the incident.
