JERSEY CITY - Authorities say a concrete block fell off a 50-story building under construction in Jersey City, injuring a police officer who was working on the street below.

The accident happened shortly before 11 a.m. Wednesday at the Bay Street site where the $194 million, 50-story tower known as Trump Bay Street is being built.

City spokeswoman Jennifer Morrill told The Jersey Journal that the officer was alert and was being treated at a hospital. The officer was expected to be released Wednesday afternoon.

Witnesses say the piece of concrete fell from possibly as high as 30 stories up.

The tower will house 447 luxury apartments. Jared Kushner, the son-in-law of 2016 presidential hopeful Donald Trump, is developing the project with KABR Group.

Kushner's spokesman could not be reached to comment.