Window washers trade overalls for superhero capes at UPMC Children's Hospital, "It's a beautiful day."

Some of the world's most famous superheroes traded crime-fighting for window washing Friday at UPMC Children's Hospital. 

It's a tradition that, for years, a group of window washers from Allegheny Window Cleaning Inc. has dressed up as superheroes while cleaning the windows to surprise patients, staff, and the community.

Spider-Man, Superman, Batman, and Captain America could be seen rappelling down the side of the hospital, waving to patients and families from outside their windows as part of a special effort to lift spirits and bring smiles to children receiving care.

"Who's your favorite?" one child was asked.

"Spider-Man!" said the child.

For the window washers behind the costumes, the day is about much more than cleaning grime.

"It's a beautiful day. We've been doing it for years. We really enjoy it," said Edward Hetrick, who is dressed as Superman. "My favorite part is watching the kids get super happy, helping their day out as they're getting a checkup or staying in the hospital."

The costumed crew knows many of the children inside are fighting battles of their own. Their mission is simple: to surprise patients, put smiles on their faces, and provide a welcome distraction from hospital visits and treatments.

Parents enjoyed the surprise as much as the children. 

"It was pretty interesting to come out and see them out there all dressed up and cleaning the windows. They can come to my house and clean the windows, too," said Melody Collins.

While Spider-Man wasn't taking on Thanos, Batman wasn't protecting Gotham City, and Superman didn't have to worry about kryptonite, the superheroes said this mission was one of their most important.

"Just hope the kids have a great day and show other people in the community that you can do simple things like this to lighten somebody's day," said Hetrick.