A World Trade Center construction worker was injured today after falling off scaffolding, authorities said.

The man was working on Vehicle Security Center near Liberty and Greenwich streets around 10:55 a.m. when he stepped on a piece of unsecured plywood and lost his footing, said a spokesman for the Port Authority.

“I just saw him there lying in a pool of blood, he was bleeding from his head,” said one construction worker at the site.

He fell approximately 10 feet, and then the plywood landed on top of him. The man was taken to Bellevue Hospital in stable condition, officials said.

“He’s doing just fine– he’s going to be alright,” said a supervisor at the construction site.