ROSELAND, N.J. (CBS/AP) — The fiancée of a Union County high school principal who died after donating bone marrow to a student in France has filed a wrongful death lawsuit. Sheronda Braker’s lawsuit filed Monday names Hackensack University Medical Center.

Westfield High School Principal Derrick Nelson died in April, several weeks after lapsing into a coma during the procedure.

The 44-year-old Nelson, who had a 6-year-old daughter, didn’t know the French teen but wanted to help nonetheless. Nelson and the teen were connected through Be the Match, a worldwide bone marrow registry network.

Nelson also served as an officer in the Army Reserve for more than 20 years and had recently re-enlisted.

The hospital didn’t immediately return a message seeking comment on the lawsuit Monday.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)