Hartford — Newtown officials are discussing the possibility of closing one of the town's seven schools amid declining enrollment, despite the ongoing construction of a replacement for the Sandy Hook Elementary School.

Superintendent Joseph Erardi told parents at a recent forum that only two schools are exempt from being considered for closure — Newtown High School and the new Sandy Hook school.

Newtown accepted a $50 million state grant for the new Sandy Hook school, which will replace the one demolished in the wake of the December 2012 shooting in which 20 students and six educators were killed. It is scheduled to open in late 2016.

"There have been no (other) decisions made at this particular time," Erardi said during an April 30 meeting with parents. "Everything is still under discussion. Everything is still under review. Everything is still being considered."

A private consultant projected last November that Newtown will lose about 200 students per year for the next five to six years, continuing a pattern that predates the shooting. Newtown's enrollment has declined 16.4 percent from just over 5,600 students in 2006-07 to a 30-year low of just under 4,700, according to that report.

The Sandy Hook school saw a 27.5 percent drop in enrollment between 2009 and 2012, well outpacing the decline in the town's other three elementary schools, which saw enrollment drop between 14.3 percent and 8.9 percent over the same period.

On Tuesday night, Erardi is scheduled to present to the Board of Education a study on the future of the district and possible configuration of schools. He declined to discuss that study in advance of the meeting.

Erardi told parents that town officials decided to rebuild the Sandy Hook school and not consider it for closing because "it's absolutely essential to have a school in that part of town."

The earlier enrollment study, prepared by the consulting firm Milone & MacBroom, cited factors such as declining birth rates and a poor housing market for the declines in the school population.

The temporary Sandy Hook school in Monroe saw a greater drop-off in enrollment in the year following the shooting, as some students transferred to private schools or moved away, according to the report.

But the school "re-set" itself quickly, returning to its previous pattern, the study found.

"Because of that we are inclined to attribute the continued decline in enrollment in 2014-15 to natural decrease, rather than clear impacts from the tragedy," the study's authors wrote.

Workers began laying foundations for the new Sandy Hook school in March and have begun installing the structural steel.

The new building will include security features such as hardened glass that can stop a bullet and rooms that can be completely secured from the inside.

Pat Llodra, the town's first selectwoman, did not immediately return a call seeking comment.