FALLBROOK, Calif. — Southbound lanes on a stretch of the Interstate 15 in North County were blocked off Sunday due to a multi-vehicle collision that killed two, including an infant, and injured four others.

Authorities were first alerted to the crash around 3:15 p.m. Sunday, located on the I-15 south of Mission Road and north of State Route 76.

Three cars were involved in the crash, with two suffering major damage. California Highway Patrol logs indicated that one vehicle had been overturned.

According to North County Fire Protection Captain John Choi, the two fatalities include one adult and one infant. No details are available yet on the age, gender, relationship between the two and what vehicle they were in.

“It’s a heartbreaking day when we lose people on our roads,” Choi told FOX 5.

One of the four individuals hurt sustained major injuries and the other three are minor, Choi said. All of the individuals that sustained an injury in the crash have been transported to the hospital for treatment.

The condition of the individual with severe injuries is unknown.

California Highway Patrol has the freeway down to one lane, as of 5:28 p.m. It is expected to stay at one lane for a few hours, according to Choi, as crews clean-up the crash.

Drivers headed southbound on the I-15 are recommended to enter on the side of SR-76 or avoid the area all together.

The cause of the accident is currently under investigation by CHP.