Marco Díaz-Muñoz kept saying the same thing when he caught up with his wife.

“They need to help them,” he told Claudia Díaz, when he met her outside the school building after the chaos.

“They need to help them.”

Normally dressed professionally and with purpose, the assistant professor’s navy button-down shirt was hanging open, haphazardly thrown back on, and his belt was missing — both taken off for wound care, though as he recalls, only his belt was used.

Díaz-Muñoz, 64, had just experienced the worst and yet all too common reality of American education — that a person can enter a place of learning and decide to end the lives of those inside, seemingly on a whim.

On Monday night, in Room 114 of Michigan State University’s Berkey Hall, where Díaz-Muñoz had been reviewing a lesson on treasure routes and piracy in the Caribbean as part of his Cuban cultural identity class, he’d found himself face to face with the masked gunman behind Michigan’s latest school shooting. The assistant professor and his wife recounted it all in Thursday interviews in their Lansing home.

Had they seen what I saw…

Paramedics swarmed the building — the help for which Díaz-Muñoz had begged, his wife said.

But by then two of his injured students, Arielle Anderson, 19, of Harper Woods and Alexandria Verner, 20, of Clawson, the ones he most worried needed that help, were “gone,” he was told.

The Backstory:‘Mom, I hear gunshots.’ Michigan State students live through a second mass shooting

At ages 19 and 20, they became two of three students fatally shot that night. Brian Fraser, 20, of Grosse Pointe, was also killed, with his death believed to have occurred as the shooting spree continued to the nearby student union. Several of Díaz-Muñoz’s other students were hospitalized.