According to the L.A. Times, coroners have been unable to determine the cause of death of 44 year-old rapper Heavy D last week through a traditional autopsy.  Officials are now awaiting the results of toxicology tests to see if those will show conclusively what killed the rapper.

The hip-hop artist collapsed on a stairwell after returning home last week while experiencing difficulty breathing.  A neighbor found him lying on the stairs and stayed with him while other neighbors phoned 911.  He was taken to an area hospital where he died about an hour later.  Police say there were no illegal drugs found in the rapper's home, but he had been prescribed medication for a cough that doctors say could have bben pneumonia.  Heavy's death is believed to medically-related, and fould play is not suspected, but the toxicology results won't be back for several more weeks.

A funeral for Heavy D will take place Friday at Grace Baptist Church in Mt. Vernon, New York, where Diddy and the Reverend Al Sharpton are exppected to speak.  BET, meanwhile, has scheduled a tribute to the late rapper, which will air as part of the Soul Train Awards on Sunday.  Curtis Blow, Naughty by Nature, Big Daddy Kane, Doug E. Fresh and others will honor the iconi musician.