HOUSTON -- NASA workers gathered on Wednesday to remember an engineer killed before the gunman killed himself, KPRC Local 2 reported.

Houston police said William Phillips, 60, shot and killed David Beverly, 62, because of a bad performance evaluation before shooting himself in the head Friday.

Hundreds of NASA employees attended a memorial service at Johnson Space Center Wednesday for Beverly, a senior avionics systems engineer.

Beverly's wife spoke at the memorial service and described the man she loved for more than 40 years as someone who lived life to the fullest and who valued his relationships with his friends and family.

“We had so much fun and joy in everything that we did,” Linda Beverly said.

Other close friends of David Beverly described him as a visionary and a good leader who never got mad but only wanted the best out of his workers.

“He was just such a good leader and a good person,” co-worker Curt Tallsman said. “He was always a man with vision.”

David Beverly was recognized numerous times throughout his engineering career and received one of NASA's highest awards, the Exceptional Achievement Medal.

Phillips took another worker, Fran Crenshaw, hostage after the initial shooting but did not harm her. She said she was able to free herself after Phillips took his own life.

NASA officials said they are reviewing their security procedures to determine if the tragedy could have been prevented. Phillips had authorized access to the building where the shootings took place.

NASA officials said they have had a confidential counseling program in place for employees experiencing conflicts at work.