CAMDEN, N.J. — A federal judge has rejected a request for an injunction to stop demolition of the 101-year-old New Jersey high school building known as The Castle on the Hill.

U.S. District Judge Robert Kugler ruled Thursday that the plaintiffs had failed to demonstrate that razing the edifice would create “concrete injury.”

The Camden High School building is set to be replaced as part of a $133 million project scheduled for completion in 2021.

Opponents, led by the Camden High School Alumni Association and the Camden High School PTO, say the building is part of the city’s cultural identity.

Plaintiffs’ attorney Matthew Litt expressed disappointment but optimism about eventual victory, saying he plans to take the case to state court.

The state Schools Development Authority says demolition could begin in a month.