In 1984, the drivers of two semi trucks loaded with a combined 40-tons of cargo were travelling together over Kelly's Mountain. Wayne Waite and Louis Gallant were communicating over the radio as they descended the mountain.
When Waite realized he had lost his brakes, he let Gallant know over the radio. The emergency brake also failed, and the truck was picking up speed on its descent.
Gallant was in front, and told Waite to drive his truck into Gallant's rear bumper, so he could brake for both of them. Waite considered jumping from the vehicle, but Gallant told him not to do so as he'd be killed. Both men knew they would have to stop before the horseshoe turn to avoid disaster.
It took half a mile to get the semis to come to a stop, but the risky manoeuvre worked.
The video above is from the TV series Rescue 911 hosted by William Shatner. The episode "Runaway Truck" aired in 1991 on CBC and is now available on YouTube.
Read more at the Rescue 911 episode Wiki.