CONCORD, Pa. — Three adults and a pregnant teenager died in a fiery crash as police pursued their vehicle in connection with retail thefts in southeastern Pennsylvania, authorities said.

The car was speeding away from a traffic stop with seven people inside Wednesday afternoon when the driver lost control while using the right shoulder to pass a vehicle that was not involved in the pursuit, state police said. Police had stopped the car shortly after troopers spotted it at a Concord Township shopping center and approached the group, who got back in the car and drove away.

The 7-mile chase on Route 322 ended after the car crossed the roadway and struck a concrete bridge embankment, catching fire. Troopers tried to get the occupants out of the car and extinguish the blaze.

The crash killed Isaiah Miller, 20, who was driving; Ikeam Rogers, 20, and Kalyn Billups, 21. Tyjana Motley, 17, who was pregnant, died a short time later at a hospital.

Emergency medical steps were taken in an attempt to save Motley's child, state police said, but they were unsuccessful.

Three other passengers in the vehicle — two adults and a 16-year-old girl — were being treated for injuries that are not considered life-threatening. No one else was injured in the pursuit or the crash, which are under investigation.