ST. PAUL — The mother of a woman critically injured in a Minnesota highway crash that killed her husband, baby and unborn child said her daughter may not survive her injuries.

Suzanne Mohn Brantly said her 26-year-old daughter, Elizabeth Calderara, is breathing only through a ventilator at Regions Hospital in St. Paul and that the family is ready to let her go.

Calderara suffered severe head and neck injuries in a Dakota County crash Monday that killed her 31-year-old husband, Jason Calderara, their 1-year-old daughter, Melody and their unborn baby. Brantly said her daughter was 35 weeks pregnant.

Nine-year-old Nicholas Calderara survived the collision between the family’s SUV and a semitrailer and is hospitalized in St. Paul.

Authorities said injuries to the truck driver weren’t life threatening.