Police have identified the deceased as Emily Dancona, a 32-year-old Philadelphia woman who taught kindergarten at Whitehall Elementary School. The other driver, a 35-year-old North Philadelphia man, was treated for injuries at Chestnut Hill Hospital.
The accident occurred April 17 at around 8:13 a.m., when Dancona's subcompact was struck by a dump truck on the 500 block of Stenton Avenue.
Two witnesses who had been driving behind Dancona told police that the subcompact had drifted into oncoming traffic moments before the accident.
The dump truck driver said he did not have enough time to react because he did not see Dancona until he reached the top of the hill. The drivers tried to swerve away from each other but still could not avert the crash, according to the witnesses.
First responders from the Barren Hill Fire Department had to pull Dancona out of her crumpled vehicle, police said; she was pronounced dead at the scene by the county coroner.
Police are working with the Montgomery County District Attorney's office to investigate the crash. They are still uncertain why Dancona drove into oncoming traffic.
"It was possible she had a medical problem beforehand - or she dropped something - but we don't know," said Officer David Schanes, a traffic accident specialist with the Whitemarsh Township Police Department.
It could take up to three weeks for toxicology test results to come back from the lab, Schanes said, and even then it might be difficult to determine exactly what caused the accident.