Officials looking into the tragic death of James Madison Univ. softball star Lauren Bernett suspect she died by suicide ... TMZ Sports has confirmed.

Rockingham County Sheriff Bryan Hutcheson tells us ... "We are in the process of conducting a death investigation into the incident and it is currently classified as an apparent suicide."

Hutcheson declined to release further details of the probe on Wednesday ... saying an official report from the Medical Examiner's Office is still pending.

"Out of respect for her family and friends," Hutcheson said, "there is no other information to release at this time."

As we previously reported, JMU officials announced on Tuesday that Bernett -- a sophomore catcher for the Dukes -- had died at the age of 20. She had just earned Colonial Athletic Association Player of the Week honors on Monday for her performances in games earlier this month.

"College athletics is great because of the people with whom we get to interact every day," JMU officials said in announcing the tragedy on Tuesday. "We are a tight family. We are grateful that Lauren has been part of our JMU Athletics community and will always consider her to be a Duke. We will miss her dearly."

"Our thoughts are with her family; her coaches, teammates and friends; the rest of our department staff and student-athletes; and the entire JMU community. JMU Nation is a close community, and we grieve together."

JMU canceled its softball doubleheader on Wednesday against Longwood following the news ... and later canceled its weekend series with Delaware as well.