HAGERSTOWN, Md. (AP) -- An autopsy concluded that traumatic brain injury from a helmet-to-helmet hit during practice caused the death of a Frostburg State University football player last month, his father said Tuesday.

Kenneth Sheely of Germantown said the family is convinced that Derek Sheely's death was accidental.

"Derek would want people to know this was an accident," he told The Associated Press in a telephone interview.

The 22-year-old senior fullback died Aug. 28, six days after he collapsed during practice at the campus in Frostburg.

His father said Derek donated his organs before he died. The university posthumously awarded him a bachelor of science degree with honors in liberal studies.

The university said in August that it would review the medical examiner's findings and its own procedures to ensure that Frostburg State is following appropriate standards for athletic practices.

Sheely was wearing a 2011 Schutt DNA Pro Plus helmet that the university selected based on the results of a Virginia Tech study of the concussion protection afforded by various brands, university spokeswoman Elizabeth Douglas said.

She said the school's Student Government Association planned to hold a memorial service for Sheely on campus Tuesday night.

Sheely's teammates are wearing helmet decals all season bearing his initials and jersey number -- 40. Other athletic teams are wearing armbands with his number, Douglas said. Sheely's family is planning another memorial service Oct. 1 at Prince of Peace Lutheran Church in Gaithersburg, Ken Sheely said. He said a church service on Sept. 1, drew 700 people. The family scheduled a second service to accommodate those who couldn't make the weekday event, he said.