A new lawsuit claim’s an anesthesiologist’s negligence caused the death of a Westfield High School principal who slipped into a coma during a bone marrow donation procedure.

Derrick Nelson died at age 44 in April because of negligence by anesthesiologist Jerry Baratta during the operation at Hackensack University Medical Center, according to the lawsuit filed Monday by David Mazie of Mazie, Slater, Katz & Freeman in Roseland. Nelson, a popular educator and officer in the U.S. Army Reserves who served in Afghanistan, had volunteered to donate his bone marrow to a teenager in France who was battling cancer.