The Transportation Safety Board has sent investigators to Pearson Airport after what they called a 'runway incursion' Thursday morning.
Essentially what that means, is a plane or vehicle was forced to take evasive action, to avoid a possible collision.
That happened just after 11 o'clock at the intersection of runway 06L and taxiway delta 3.
It appears to have been two aircraft, a smaller jet operated by American Airlines and a United Airlines jumbo jet that nearly collided.
The American Airlines flight was landing from New York, while the United flight was taking off on the way to Chicago.
There were no injuries and no collision happened.