A Southwest Airlines plane descended prematurely on Wednesday over Oklahoma City, startling residents miles from the airport, before regaining altitude and then landing safely.

After beginning a descent from 39,000 feet, the Boeing 737-800, flight No. 4069 from Las Vegas to Oklahoma City, was still nine miles short of the airport when it reached an altitude of about 525 feet, according to a report by The Associated Press that cited Flightradar24 data. The plane then ascended again to about 3,000 feet before landing successfully at its planned destination, Will Rogers World Airport, at 12:16 a.m. local time.

An automated warning was triggered by the low altitude, and an air traffic controller alerted the pilots, the Federal Aviation Administration said in a statement.

“Southwest 4069, low altitude alert. You good out there?” the controller can be heard saying in a recording from LiveATC.net provided to The Oklahoman newspaper.

The F.A.A. said it was investigating the incident.

The plane’s low point happened roughly over the city of Yukon, just west of Oklahoma City. Some people in the area said on social media that they were alarmed by the noise and low path of the jet.

“Southwest is following its robust Safety Management System and is in contact with the Federal Aviation Administration to understand and address any irregularities with the aircraft’s approach to the airport,” the airline said in a statement.

There is no indication that the incident was caused by any mechanical failure, but Boeing planes have been involved in several recent safety incidents.

Most notably, a door panel blew out of an Alaska Airlines 737 Max 9 jet in January, leading to the temporary grounding of some planes, a company plan to improve safety and an apology from the company’s chief executive, Dave Calhoun.