Kendall Berry, a quarterback at Haines City High School who went on to play running back at Florida International University, was stabbed to death in an incident on the school's main Miami campus Thursday night.
Only hours after the stabbing, the university president said in a video message that officials "will not rest" until his attacker is found.
"Our hearts are heavy," a somber FIU president Mark B. Rosenberg said Friday morning.
Berry was stabbed late Thursday night, after Miami-Dade police said the 22-year-old junior was involved in an argument with another man outside the front doors of the school's student recreation center - one of the spots where the football team trains. Several witnesses to the incident were being interviewed, Miami-Dade Police Detective Javier Baez said.
FIU opened as scheduled Friday morning, with increased security for students and grief counseling available. Students living in residence halls were advised to keep doors locked, and any person at the university could be escorted around campus if desired.
Members of the FIU football team were already receiving counseling, and a football coaching clinic scheduled for Friday and Saturday has been indefinitely postponed.
"Last night, we lost a well-liked student who was a tireless worker in the classroom and on the ball field," Rosenberg said. "Like so many of our students, Kendall Berry had positive energy and a bright future."
Berry died on the way to a hospital, Baez said, adding that he did not know if Berry and his attacker knew each other.
A person was "detained and questioned" but was released and "is not a currently a suspect," Detective Aida Fina-Milian said Friday morning.
Spring football practices have been postponed. No final decision has been made about when to hold the program's annual spring game, which for now remains scheduled for Wednesday.
"In our sorrow, we must come together," Rosenberg said in his message to the university community. "Our campus is safe. Now more than ever, you must tell this story. ... Even while we mourn Kendall and express our sympathy to his family and friends, we must not let this heinous crime overshadow the incredible track record for safety that we have."
Outside the rec center Friday morning, police tape was stuffed into a trash can and an orange "X" was spray-painted on the ground near the front doors. A sign said the building was scheduled to reopen at noon Friday.
Other than the university statement, FIU's athletic department did not have an immediate comment.
Television images showed several students, including some identified as FIU athletes, hugging and crying Thursday night near the spot where the stabbing took place, shortly before the university released official confirmation that Berry died from his injuries. One student dropped to her knees in grief just inside the doorway, screaming.
FIU senior Martha Carvajal, 25, said she heard helicopters and saw police lights while she studied on campus.
"I was startled by it," Carvajal said Friday. "When I finally found out, I was like, 'Oh no, somebody actually got killed here."'
Berry had 164 all-purpose yards in limited use as a freshman in 2007, appearing in all 12 FIU games that season. He sat out the 2008 season with a knee injury and then had some breakout moments in 2009, rushing for three touchdowns in a span of 13 minutes against Middle Tennessee on Nov. 7 and following that up with two more scores the following week in a win over North Texas.
Berry had seven brothers and sisters, the university said. A memorial service is being scheduled, Rosenberg said.
"Last night, his grief-stricken mother described Kendall as a negotiator, not a fighter," Rosenberg said. "We will not rest until the perpetrator of this crime is brought to justice."
Berry finished last season with a team-best seven touchdowns, despite not playing in the season's first seven games because of continued rehab from the knee injury.
"When you put the football in his hands, that kid can do some unbelievable things," FIU football coach Mario Cristobal said late last season of Berry.
FIU officials said they did not recall another killing on the school's campus.
"It's a very safe campus and we strive every day to keep it that way," said Lt. Rick Torres of the FIU police department.
At Haines City High, he played in the Hornets' triple-option offense at quarterback in his last two seasons after playing running back as a sophomore. He also ran track in high school.