NEW CASTLE, Ind. — A couple from Minnesota was killed and their 13-year-old granddaughter seriously injured when the vehicle they were in was struck from behind by a semitrailer on an Indiana interstate and pushed into the back of a different tractor-trailer and another vehicle, authorities said.

Sylvia Shaw and John Shaw, both 66 and from New Brighton, died in the accident about 12:15 p.m. Saturday, Henry County sheriff’s deputy Landon Dean said. Traffic was slowing for construction work about 1.5 miles ahead when the accident occurred, he said. It took emergency personnel nearly an hour to pull 13-year-old Katrina Tucker of Minneapolis from the vehicle.

“When you see the vehicle, you wonder how anyone could have survived that,” Dean said.

The teenager was listed in stable condition Sunday in the intensive care unit at Riley Hospital for Children in Indianapolis with a broken hip, arm and leg, Dean said. He said Tucker’s parents arrived at the hospital Sunday morning.

Dean said the Shaws had taken their granddaughter sightseeing in Washington, D.C., and they were headed to visit family in Indianapolis when the accident occurred.

Dean said the investigation into the crash continues, including whether the driver of the semi that crashed into the Shaw’s vehicle had driven more hours than allowed under federal law.