Hepner was a passenger in the Toyota Camry that collided with an SUV on the beltway, then spun out of control after 6:30 p.m., according to WBAL TV.
Virgil Ruben Carlson, 91, of Parkville, was driving the Toyota, which hit the concrete barrier on the right side of the highway twice, ricocheted over to the barrier on the left side and came to rest, WBAL TV said.
A motorist on the highway pulled over and helped Hepner and Carlson get out of the vehicle as it caught fire, according to Fox 45.
Hepner was taken to the hospital, where she was pronounced dead. Carlson was injured, WJZ reported.
The driver of the other vehicle, a Nissan Rogue, was not injured, according to WJZ.