A Delta Air Lines jet undergoing maintenance testing rolled off a taxiway and down an embankment this morning at Atlanta's Hartsfield-Jackson International Airport.

No one was injured in the incident, which involved a Boeing 737-700 and occurred around 5:00 a.m. ET, according to The Associated Press. There were no passengers on the jet, which was not operating a scheduled flight at the time.

Delta spokesman Eric Torbenson tells The Atlanta Journal-Constitution two Delta mechanics were testing the jet's engines when they "experienced a problem with the plane's braking system."

The aircraft then began to move, eventually rolling off the taxiway and over the embankment, according to MSNBC.com.

Torbenson tells the Journal-Constitution the jet sustained "significant damage." By afternoon, a crane had been brought in to move the jet, according to AP.

The newspapers says Atlanta's Runway 26-L closed following the incident. But, as of 9:30 a.m. ET, flights were departing -- but not arriving -- on that runway, according to the Journal-Constitution.

And the incident was causing delays at the airport as well. Delays averaging 30 to 45 minutes were being reported as of noon ET because of a "disabled aircraft," according the Federal Aviation Administration's flight delay map.