Hundreds of people gathered in St Bees Priory on Saturday night after the school's governors rejected a last-minute plan to keep the school open.
Professor Frank Woods said the decision was not taken lightly.
The meeting was occasionally heated, with parents calling for Professor Woods to resign.
The Rescue Group, which raised £2m, said it now accepted the school would not re-open in September 2015.
The group's chair Mark George said he was "heartbroken" that their bid had not been successful.