"closed it off" is a correct and commonly used phrase in written English.
It means to block or prevent access to something. Example: The construction crew closed off the section of the road where they were working.
The cops had closed it off at Fifth Avenue.
The guy swooped the net up, closed it off, and there he went".
The tales were exaggerated but not without foundation, for four or five bootleggers who had sizable operations there had effectively closed it off to the law.
In previous years revellers have jumped from the nearby bridge into the river, leading to so many injuries that police closed it off for several years.
I really wanted to see him -- to see what he had gone through -- but Frank said: "The government has closed it off to everybody but forensics.
Volendam is a fishing village on the coast of what was called the Zuider Zee until 1932, when the Dutch government built a dike that closed it off from the sea.
A contractor added cabinet doors to close it off from the kitchen.
"From my point of view, it's a public park, and they're closing it off and privatizing it for people to make money," Ms. Porter said.
The explosion that sank the drilling rig came less than a day after workers finished pumping concrete into the well, a step toward closing it off temporarily.
The closet was a shallow cavity with a wooden rod braced across, a faded cretonne curtain on a string closing it off from the rest of the room.
But since the church bought the block from the city three years ago for $8.1 million, closing it off to vehicles but not pedestrians, the sides have wrestled over its control.
