A low flying crashed into a moving train on the evening of June 1 in Burlington, Wisconsin. The unusual crash sent in the hot air balloon to the hospital with life-threatening injuries, and two of them were transported via helicopter for immediate medical attention.

Burlington Police responded to the report of a hot air balloon and freight train collision on Calumet Street at 8:15 p.m. local time. The initial cited witnesses who said the hot air balloon appeared in distress shortly before crashing into a northbound train. The balloon is owned by the Lake Geneva Balloon Company, and the train is owned and operated by the Canadian National Railway.

A report from showed the aftermath of the crash, but video footage of the collision was captured by a driver and later released by .

Local news reports from cited one witness who said the hot air balloon bounced off of a building prior to the collision. That account said it was the train that struck the hot air balloon, but a Burlington Police statement released on June 2 provided further details from the hot air balloon pilot:

The pilot reported while attempting to land the hot air balloon in the 400 block of Calumet Street, the gondola touched down and the balloon became entangled with a Northbound Canadian National train.

Despite the pilot testimony, video footage and eyewitness accounts, the cause of the collision is unknown. The crash is currently under a joint investigation led by the National Transportation Safety Board (NTSB). The investigation involves the NTSB, Burlington Police and the Federal Aviation Administration. There was even a from the Balloon Federation of America warning against any speculation.

Police initially claimed the Canadian National Railway was also participating in the investigation, but the company has since declined to comment on the crash, saying local authorities should handle any inquiries.

The good news is that the remarkably improbable crash did not end in loss of human life. The hot air balloon pilot and both passengers have been released from the hospital and are now recovering from their injuries. No word on the state of the balloon, however, or that of the railcar from the train.