POINT LOOKOUT, N.Y. — Thousands are expected at a seaside service on Long Island to commemorate the 15th anniversary of the Sept. 11 attacks.

Officials in the town of Hempstead will converge at Point Lookout, on the south shore of Long Island. On Sept. 11, 2001, many people watched the attacks on the World Trade Center from the seaside vantage point.

The service begins at 7:30 a.m. Sunday and will feature a new monument that shows a reverse shadow box of the twin towers. That will be accompanied by a 35-foot long mural.

During the program, participants will be able to write inspirational notes and names of victims on the mural.

The town also plans to unveil a large rendering of a permanent 9/11 monument planned for Point Lookout Town Park.