On Monday, North Park Elementary School in San Bernardino, California was the scene of a tragic school shooting.

According to all available reports, a man walked into his estranged wife’s classroom, armed with a large caliber revolver, and shot her to death.

Two children, aged eight and nine years old, were also severely injured in the attack, with eight-year-old Jonathan Martinez, succumbing to his injuries, according to the Loma Linda University Medical Center. The nine-year-old boy, who remains nameless, is confirmed to be in stable condition.

Jarrod Burguan, the San Bernardino Police Chief, has indicated that the two boys were standing behind the primary target of the shooting, special needs teacher Karen Smith, aged 53, when shots were fired.

Smith’s estranged husband was the perpetrator of the attack. Burguan stated that the shooter walked into Smith’s classroom, armed with a large caliber revolver, and opened fire. Shortly after the incident, the shooter committed suicide.

Smith’s husband, according to Burguan, was able to sign in at the front desk of the school, claiming that he wanted to drop something off with Smith. When he entered Smith’s classroom, Burguan said that “He came in, and very, very quickly upon entering the classroom started shooting.”

The couple had, according to Burguan, been married only a few months, with the couple being estranged for one month. “No one has come forward to say they saw this coming,” Burguan said.

The rest of the 600 students in the school were evacuated to California State University, San Bernardino. Those children were soon brought back by buses to a local high school, where they were reunited with their families.