A plane full of travelers at Toronto Pearson International Airport in Canada was forced to evacuate on emergency slides Friday evening after the aircraft next to them burst into flames.

A video of the collision shows the moment a WestJet Boeing 737 with 168 passengers on board hit an empty Sunwing aircraft, causing the Sunwing jet to catch fire.

Terrified WestJet passengers could be heard screaming in the video, as what appeared to be a fireball erupted from the other aircraft’s wing.

Flight attendants eventually evacuated the passengers, who had just landed at the airport after flying in from Cancun, Mexico, on emergency slides.

WestJet passenger Gustavo Lobo said he and other passengers heard a crunch when the Sunwing jet collided with their aircraft.

“Out of nowhere there was an audible crunch and the plane rocked slightly,” Lobo told CBC News. “We looked out the window and saw that the plane had backed up into us. Everyone was a little shocked and kind of chuckling at the situation.”

Sunwing tweeted that the accident had been caused by the ground-handling service Swissport, which is a third-party contractor many airports use to handle aircraft and cargo on the ground as planes arrive and take off.

We are aware of an incident that occurred shortly after 6pm this evening at Toronto Pearson Airport where a Sunwing aircraft, under tow by our ground handling service provider, came into contact with another aircraft. — Sunwing Vacations (@SunwingVacay) January 6, 2018

There were no Sunwing crew or passengers onboard at the time of the incident. We are awaiting further information from Swissport and will provide more details as they become available. — Sunwing Vacations (@SunwingVacay) January 6, 2018

Toronto Pearson Airport released a statement via Twitter announcing that all WestJet passengers arrived safely at the terminal and cleared customs.

Update: As of 21:00, all Westjet passengers have been safely returned to the terminal and are being cleared through Canadian customs. More info available here: https://t.co/b9cBJMg7uF. https://t.co/5hnMRb9TIF — Toronto Pearson (@TorontoPearson) January 6, 2018

Canada’s transportation safety board said it would be investigating the incident.