ST. LOUIS - A 6-year-old boy was killed in a north St. Louis shooting Wednesday evening.

It happened near the intersection of West Florissant and Vera. Police say a minivan carrying a family had just pulled out of O'Fallon Park when someone in a black SUV pulled up and opened fire on them.

The father says he returned fire, and that continued back and forth for several blocks.

Police say Marcus Johnson was shot in the chest was rushed to the hospital by a police officer where he was pronounced dead.

During the incident, Marcus' 15-year-old brother was shot in the ankle and a 69-year-old man was also shot in the knee. Family members say they're expected to be ok.

Marcus' father tells police he doesn't know who was shooting at them or why anyone would shoot at them. An investigation is underway.

Marcus' sister Tynesha Prince says she's trying to support her mother during this difficult time.

"It's kind of hard on my momma, 'cause she's pregnant and now to hear that, it's just breaking my heart.

Marcus' grandfather, Kelvin Johnson says the young boy was lively and full of joy.

"He always wakes up with a smile and he shares that smile with the whole house," he said.

Marcus was a kindergartner at Highland Elementary School. Thursday, his classmates made pictures and cards for his family.

The school district will have counselors on standby to help students process any emotions they are feeling.