No one could believe what they were seeing in Chicago’s West Loop on Tuesday morning.

“We just look up, and saw a man scaling the building, but we didn’t pay much attention to it at first, because we thought it was a window washer,” said street minister Allan Swint.

Swint and dozens of others near Madison and Clinton streets got quite a surprise start to their day when a man began scaling the nearly 600-foot tall Accenture Tower without a rope.

“I’ve never really seen anything like that, so I wanted to see how he’d get down or how they got him down,” said West Loop office worker Nana Busia.

People first noticed the climber around 10 a.m. News helicopters captured images of the climb, and plenty of others in neighboring building and on the ground used their cellphones to record it too.

Maison Des Champs has taken credit for free climbing the 40-story building.

The anti-abortion activist has done climbs like this over a half dozen times before in other cities, hoping to raise money for charities supporting his cause.

Both Chicago police and fire dispatched resources to what they call a “publicity stunt” and blocked off streets in the area for about an hour for everyone’s safety.

No one was injured during the ordeal. Once he got to the top of the building, the climber was taken into custody and arrested by Chicago police, who said charges are pending.