Witness Robert Lee said he and his wife were on their way to a furniture store when they saw the accident on the FM 518 / I-45 northbound Feeder road.
Lee, who is recently retired from the U.S. Coast Guard, said he rushed over to the truck and opened the door to begin helping the passengers.
He said before he knew it, there was an entire group of people lending a hand to assist him.
Together, Lee and the other good Samaritans pulled the family members out of the flipped truck, including children and the family's Great Dane.
Lee said all members of the family were okay after the accident.
WATCH: Full interview with former U.S. Coastguardsman who helped after crash