A man has died after stumbling into a Flatbush barbershop with stab wounds.

Curtis Maharaj, owner of Gentleman's Quarters Salon on Church Avenue, says the young man came in off the street around 8 p.m. Tuesday.

"He started saying 'I can't breathe,'" says Maharaj.

Police have identified the young man as 19-year-old Mamadou Bah, who they believe lived just a few blocks away from the barbershop.

Maharaj says he'd never seen the teen before.

"I just thought he was somebody acting crazy to be honest with you until he started saying, ‘call 911,’" says Maharaj.

He says he didn’t even realize Bah had been stabbed until the 19-year-old took off his jacket.

"He kept saying my belly is paining, my belly is paining. Then he took off his jacket and I saw blood, so I was like 'yo, you got hurt' and I called back 911," says Maharaj.

He says first responders arrived shortly and put him in an ambulance.

"I could have sworn he would have been patched up and they take him home," says Maharaj.

Despite Maharaj's optimism, Bah was pronounced dead at the hospital.

Police are investigating why he was stabbed and what led up to the stabbing.

Anyone with information is asked to call police.