The 17th Annual World Wildlife Fund's CN Tower Climb seen almost 5000 climbers get up at 6 am to climb the stairs of the CN Tower.
The tower has 1,777 stairs. The fund raiser is to raise money and help the impact of global warming.
People have trained for months for the climb. One little girl did it for the panda bears. She found out there was only 1,600 left in the world so she wanted to do her part to help the bears.
The event this year is expected to raise $800,000. That is a lot of stairs to climb but it is for a great cause.