A United Airlines flight destined for Canada was diverted on an emergency basis to Denver International Airport when fire was seen erupting from one of its engines—initiated, incredibly, by a rabbit.

United Airlines Flight UA2325 had only left Denver for Edmonton when passengers and staff were startled by a deafening explosion. A short while later, fire was seen erupting from the plane’s number two engine.

On cockpit audio, the pilot is heard requesting an engine fire inspection. The reason would soon be clear.

“Rabbit through the number 2 [engine], that’ll do it,” the pilot called.

Passenger Scott Wolff explained his terrifying ordeal to Good Morning America:

“Every few seconds there was a backfire from the engine, a huge fireball behind it. Everyone in the plane then panicked.”

Wolff heard the boom when the rabbit was sucked into the engine, which shook the plane and notified all passengers on board.

The plane, with 153 passengers and six flight attendants, made a safe landing in Denver around 8:05 p.m., the Federal Aviation Administration (FAA) reported. United Airlines officials confirmed the incident, stating:

“United Airlines flight UA2325 from Denver to Edmonton returned to Denver safely to deal with a suspected wildlife strike.”

Luckily, no injuries were reported in this episode.

It is not the first time Denver Airport has seen an engine scare. American Airlines flight had to be evacuated last month when one of its engines erupted into flames.

In that case, all six crew members and 172 passengers were safely evacuated, though 12 people required hospital treatment for minor injuries.

In the instance of United Flight 2325, the aircraft has been taken into investigative custody for inspection prior to resuming flight status.

While bird strikes are a well-known threat to planes, collisions with rabbits are extremely rare—making this incident a bizarre and exhilarating wake-up call as to just how unforeseen air travel can be.