Some 120 airline passengers and crew members are thankful to be unharmed today after the pilot of their Toronto-bound flight was forced to declare a state of emergency in mid-air.

Air Canada flight 715 from New York's LaGuardia Airport to Pearson International in Toronto is said to have lost one of its main landing wheels while taking off around 2 p.m. on Tuesday.

"The aircraft, an Airbus A319, experienced an issue with one of its six tires on take-off," said Air Canada in a statement, acknowledging that the pilot had declared an emergency mid-flight "to ensure the aircraft had priority for landing when it arrived in Toronto."

Update LOST WHEEL Air Canada #AC715 from New York now inbound for landing in Toronto runway 23. Emergency services standing by. Tower reports one wheel on main landing gear completely missing. Wheel possibly lost on departure from LGA. https://t.co/2uh6brvnzQ pic.twitter.com/5mqCfDeJdW

— Tom Podolec Aviation (@TomPodolec) February 18, 2020

Postmedia reports that crew members told passengers to "assume the crash position" shortly before the plane touched down in Toronto around 4 p.m.

Emergency crews were standing by in case the unthinkable happened.

Fortunately, the plane landed safely at Pearson — albeit without one of the two wheels on its right-side main landing gear.

Thankful to be on the ground safe and sound! My thanks to the captain and crew for their excellent work and communications. Well done https://t.co/1VCFwadFnX pic.twitter.com/meVTB8bDDB

— cameron milne (@digitalcam123) February 18, 2020

"The Airbus jet normally has two large wheels on each of the two main landing gears, and two smaller wheels under the nose," explained the Canadian Press. 

"Most airline jets have more than one wheel on a landing gear, and wheels and tires are designed to withstand the extra load if another one fails."

And thank goodness for that.

So thankful for the pilot & crew for their excellent communications and a smooth landing! @aircanada handled this amazingly. pic.twitter.com/nP6WoLZiMo

— Jennie (@jnniechng) February 19, 2020

"Thankful to be on the ground safe and sound! My thanks to the captain and crew for their excellent work and communications. Well done," wrote one of the passengers aboard flight AC 715 on Twitter.

"So thankful for the pilot and crew for their excellent communications and a smooth landing!" wrote another.

"Air Canada handled this amazingly."