HAWTHORNE, N.Y. (AP) -- Preliminary autopsy results have found no medical cause that could explain why a woman drove the wrong way on a suburban New York parkway, ending in a crash that killed eight people.

State Police investigator Shannon Morrison said Tuesday that the autopsy of Diane Schuler didn't find any conditions like a heart attack or an aneurysm.

Schuler drove nearly 2 miles in the wrong direction on the Taconic State Parkway in Westchester County on Sunday. Her minivan crashed into an SUV before bursting into flames. The Long Island resident, her daughter and three nieces died; three men in the SUV were killed.

Morrison says investigators hope a toxicology report and accident reconstruction will reveal more about the crash. Both could take weeks to be completed.