A substitute teacher who died after being punched in the chest by a fourthgrade student had heart disease, an autopsy showed Wednesday.
Nedra Morris, 51, collapsed Tuesday afternoon in the hall outside her classroom at Marshall Elementary School after struggling with the boy.
Police said the boy refused to do an assignment, then apparently hit Morris several times in the chest.
School spokesman Chester Edmonds said no adults saw what happened, and students gave conflicting statements.
Medical examiner Dr. Michael Graham said he is still investigating but believes Morris died from abnormal heart rhythm. Investigators still must determine whether that was brought on by the stress of the altercation or by physical contact, he said.