Hundreds of people put their endurance to the test Sunday morning at the seventh annual Towers Climb.

The event takes place at One World Observatory to help a special cause that was born out of 9/11.

Participants started their climb at around 5 a.m. and embarked on over 2,000 steps.

Climbers from all over the world proudly crossed the finish line of the 102nd floor for a gold medal.

For many who knew someone who died in 9/11, it was an emotional climb.

“Climbing up those stairs, we’re passing wounded warriors, men who sacrificed their legs, sacrificed other limbs going down these stairs. And they’re thinking ‘us’, Chris Burke said. His brother died in 9/11.

Burke says that when considering the sacrifice his brother made, he would climb those stairs again and again.

Over 1,000 crossed the finish line at the sold-out event to honor fallen heroes.