An Islip Town Hall meeting got heated Thursday night as advocates and critics debated the proposed $4 billion Heartland Town Square project.

The Heartland Town Square would transform 451-acres on the former grounds of Pilgrim State Hospital into a development with a mix of apartments, offices, shops and restaurants.

Developer Gerald Wolkoff is seeking the green light from the Town Board for a zone change. Wolkoff says the project will help stop the so-called "Brain Drain" of young Long Island professionals leaving to live in other states because of the high cost of living.

"I'm going to make a magnificent development and make it affordable for our young people," said Wolkoff.

Developers say the project could bring some 20,000 jobs to the Brentwood area.

Mary Calamia, of Holbrook, says her concern is taxpayers shouldering the burden for the project.

"We're going to have to pay for all of this. We're going to be paying for their infrastructure changes, the additional services needed, wear and tear on the communities," said Calamia.

The planning board will make a recommendation to the Town Board regarding the rezoning application. A date has not been set for a final vote.