HAMBURG, Pa. — A fifth person has died from his injuries suffered in a series of related crashes on an eastern Pennsylvania interstate, a coroner said Thursday.

State police are still investigating the twin crashes on Interstate 78 in Berks County.

The first crash happened around 8:30 p.m. Tuesday when a 69-year-old Georgia woman who was driving an empty school bus failed to stop in a construction zone near the Hamburg exit and slammed into the back of a sedan, killing the driver, authorities said.

The bus then went over the top of the sedan and rear-ended an SUV, killing the front-seat passenger, police said.

About two hours later, the 64-year-old driver of a tractor-trailer that was being detoured off I-78 because of the earlier crash failed to slow down for stopped traffic and rear-ended a van, causing a chain-reaction crash involving three other vehicles.

Also killed were a backseat passenger in a sedan and an SUV driver, police said.

The victims in the first crash were identified as Thalia Jackson, 25, of Easton; and August D. Schwartz, 20, of South Whitehall Township.

The victims in the second crash were identified as Joshua D. Del Toro, 21, of Reading, Jonny L. Young, 54, of Loyalsock Township, and Yalibet Lopez-Perez, 24, of Reading.