Police said 22-year-old Garrett Barker and 21-year-old Kelsey Halterman were driving over an icy I-215 overpass near North Salt Lake when their truck lost control and slid along the guard rail.
The truck then flipped over the railing and landed near the train tracks below. Both passengers were ejected. The couple and their four dogs were all killed in the crash.
One witness said the couple was driving around 65 miles an hour, which police say was too fast for icy conditions.
Officers say the woman was 36 weeks pregnant, and was taken to Lakeview Hospital where the baby was removed. The child was then taken to Primary Children's Medical Center but its injuries were too severe, and it also died.
Tanner Nelson was a friend to the victims, and he said the couple were starting out in life and determined to help others.
"They were engaged and going to get married and have a baby and start a life, really," he said."They had a great life where all they did, pretty much, was give back to people and animals."