The video above is from a May 1 story about Cosgrove-Flax's death. WICHITA, Kan. (KSNW) -- The death of a Kansas sailor who died during a naval training exercise in April has now been ruled a homicide. The U.S. Navy confirms to KSN News that the death of Master-at-Arms 3rd Class Lyndon Joel Cosgriff-Flax death was due to negligent homicide, not accidental. Cosgriff-Flax died Sunday, April 28, during a training and area familiarization exercise on the York River in Virginia. He was part of a harbor security boat team when he reportedly fell overboard and sustained fatal injuries. The Navy Region Mid-Atlantic Public Affairs Office says a fellow sailor of Cosgriff-Flax has been charged with negligent homicide, making a false official statement, and two counts of dereliction of duty in his death. The Navy says the sailor will remain unnamed until charges have been referred. KSN spoke to Cosgriff-Flax's family shortly after his death. He played football for Eisenhower High School in Goddard before graduating and enlisted in the Navy in 2021. His mother, Stephanie Cosgriff, told us he wanted to be a police officer at an early age but found his calling to protect others. Master-at-Arms 1st Class Simone Campbell, who served with Lyndon, said he always encouraged his fellow sailors to succeed.  “He was a great example of protecting others, leading from the front, being the humorous guy that he was, a big tall awesome man that he was,” said Campbell. Judge sentences Topeka woman in deadly crash that killed 3 local girl scouts, including her daughter A memorial service took place in Yorktown in July, attended by his fellow sailors and his family. NWS Yorktown’s Commanding Officer, Captain Dan Patrick spoke at the service. “We are going to miss him, and our Navy will never forget his service," said Captain Patrick. "The Sailors that he served with will never forget him, and I will never forget him. Your tears of grief are very much shared by every Sailor and civilian here, and are especially shared by members of our Security department.” A court date for the sailor charge in Cosgriff-Flax's death has not been set.