Police in Texas are hunting for whoever tossed a large rock off a highway overpass after it crashed through the windshield of a passing car, killing a young mother of three.

Keila Flores, of Waco, was sitting in the passenger seat of a car driven by her boyfriend, Chris Rodriguez, with her three children in the back seat when someone heaved a football-size rock from a railroad overpass on Interstate 35 in Temple late Saturday, police said.

Flores was rushed to a hospital, but died from her injuries the following morning. An autopsy will be conducted, police said.

Rodriguez, who is now calling for the person who tossed the rock to surrender, said his life was forever changed in an instant.

“It happened so quick,” Rodriguez told KCEN. “It literally, like, the front windshield just, like, exploded.”

Rodriguez said the family was headed to Austin at the time. He pulled over immediately after the rock crashed through his windshield and began administering CPR with the help of another motorist who pulled over to help him.

“This individual stopped and helped me,” an emotional Rodriguez said. “He didn’t have to, but he did.”

Police spokeswoman Ellen Morton told The Post that no suspects had been identified in the case as of Tuesday. No additional information was available, she said.

The incident, which is being investigated as a homicide, is believed to be the first of its kind in the town of roughly 75,000 residents north of Austin, according to Officer Shawana Neely.

“We really need to bring this person to justice to show that we’re not going to tolerate things like this in the future,” Neely told KCEN.

Rodriguez, meanwhile, said he wants to know why someone would randomly target someone whom he loved so dearly and who brought immense joy to her three children.

“What was the reason for it?” he continued. “Was it just enjoyment? What do you get out of hurting an innocent person for no reason?”

Rodriguez told “Good Morning America” on Tuesday that he’s now worried about Flores’ children, who were not hurt but saw their mother in such agony.

“It’s something you don’t forget,” Rodriguez said. “I just hope that it doesn’t affect them in the long run, and that they will realize what a good mother they had.”

Investigators have interviewed a person of interest in the case, which is being probed as a homicide, Rodriguez and Flores’ relatives told ABC.

“Her death won’t be in vain,” Rodriguez said. “Justice will take over, and I do believe that they will do their job and they will find this person.”