Some of the biggest drama at the U.S. Open took place in the sky just east of the course Thursday morning when a blimp advertising for PenFed Credit Union deflated, burst into flames and crashed.

The blimp went down about 11:15 a.m. near Highway 83 and Highway 167. The crash site was about a half mile from the Erin Hills golf course where thousands of people gathered for the first morning of competition.

The pilot was transported by Flight for Life from the area of the crash just after noon. No one on the ground was injured.

The blimp was operated by AirSign, an aerial advertising firm with operations across the country.

The pilot is OK but suffered some burns, a spokesman for AirSign said in a telephone interview from the company's Florida office. The company web site says it specializes in banner, blimps and sky writing.

The pilot remained with the blimp as it slowly descended to the ground.

"He stayed with the blimp until it went down," the spokesman said, adding that a crew member on ground pulled the pilot from the wreckage.

Early Thursday afternoon the company tweeted: "Thanks to everyone for your concerns, the blimp pilot is being taken to the hospital but is expected to be ok. No details on cause of crash."

Rescue crews from numerous area fire departments responded to the scene.

"It started deflating, and then it started going down," said Bryan Rosine.

"They were trying to give it some throttle and it didn't go up," he said. "Then there was a bunch of kabooms and smoke clouds."

Another witness, Tim Guetzke, said "the side started deflating. One side was going in. As it headed toward the ground, it caught fire."

The blimp landed in a farmer's field near a stand of trees and looked like a large deflated balloon. Videos show flames and explosions after the wreckage hit the ground.

The sign on the blimp advertised PenFed Credit Union, also known as the Pentagon Federal Credit Union. The nations's third-largest credit union with assets of about $22 billion, PenFed serves about 1.5 million people with connections to the military and has branches in 10 states.

Earlier Thursday morning, AirSign tweeted about the blimp's arrival and encouraged visitors to share photos.

The blimp took off from a small privately operated air field not far from the crash site, said Dan Coffey, owner of the Air Strip WN75.

"They were going to use it all week," Coffey said. "He was flying it for hours. I don't know if the wind caught up with him or what."

Coffey said that the accident was extremely unusual.

"These airships are FAA approved. They make sure that every one is inspected," he said. "This is an extremely rare accident."

Terry Williams, a spokesman for the National Transportation Safety Board, said the agency has launched an investigation into the incident and has dispatched an investigator to the scene.

A statement distributed by the United States Golf Association said the blimp was not affiliated with the USGA or the U.S. Open.

"Our thoughts and prayers are with the pilot at this time," the USGA statement said.

Earlier Thursday morning, AirSign tweeted a picture: "The beautiful @penfed blimp is flying high over the US Open today!"

The company also tweeted a picture of the golf course taken from the blimp.

What I presume is smoke from the blimp crash in the background.

— Bill Cooney (@PGATOUR_Cooney) June 15, 2017