Boston police are investigating the apparent suicide of a crew member aboard a yacht owned by Red Sox owner John Henry that was docked at Rowes Wharf.

Boston police spokeswoman Cheryl Fiandaca said firefighters and police responded to the Iroquois for a medical emergency about noon.

Fiandaca said rescuers found a 28-to-30-year-old male in cardiac arrest. Efforts were made to revive him, but he was later pronounced dead.