The Mother of a Locust Valley teen who died after falling off a sailboat is suing the chairman of Nassau University Medical Center and his wife claiming they are responsible for her son’s death.

The lawsuit filed by Kathleen Koch says her son was served alcohol despite being underage and intoxicated at a party allegedly hosted by Matthew and Kerry Bruderman last May.

Court documents say Jack Koch and another intoxicated, underage guest left the party in a sailboat.

Koch’s body was found off the coast of Caumsett State Park two weeks later.

News 12 reached out to NUMC for comment from the chairman but have not heard back.