A man terrorizing people on the streets in Brooklyn with what appeared to be a firearm was fatally shot by cops — who later determined the weapon was not a gun but a metal pipe.

Saheed Vassell, 34 — whose family said he suffered from bi-polar disorder — was brandishing the curved metal pipe and pointing it at people at a bus stop at Utica Avenue and Empire Boulevard in Crown Heights at 4:40 p.m., according to police.

Three witnesses called 911 to report that a man wearing a brown jacket was pointing “what was described as a silver firearm at people on the street.”

Surveillance footage from a Utica Avenue store shows Vassell pointing the pipe like a firearm at a person who is walking into a store.

One 911 caller followed Vassell’s movements as he was walking along Montgomery Street while continuing to point the “weapon,” police sources said.

At Utica Avenue, Vassell “took a two-handed shooting stance” and aimed the metal pipe directly at arriving officers, according to NYPD Chief of Department Terence Monahan.

Four cops, three in plainclothes and one in uniform, then fired a total of 10 shots, striking Vassell several times.

Monahan stressed that the officers were responding not to a call of a disturbed person — which might have been handled differently.

“This was a call of a man that 911 callers felt was pointing a gun at people on the street. When we encounter him, he turns with what appears to be a gun at the officers.”

The man’s father, Eric Vassell, said his son suffered from bipolar disorder and drank but was “never a bad person.”

The dad said cops could have handled the situation differently.

“There must be a way to save this person than to kill them,” he said. “Aren’t the police trained how to defend [themselves] and prevent killing a mental person?”

Vassell was rushed to a hospital, where he died.

Afterward, people gathered to decry to police-involved shooting.

“They didn’t try to help him!” a woman yelled. “That wasn’t CPR!”

But police said officers immediately rendered aid to Vassell and called an ambulance.

A man wearing a 67th Precinct clergy-council crisis-team jacket tried to calm a woman at the scene who was visibly upset.

“They don’t want to bridge the gap between us, they want to kill us,” the woman said.

Additional reporting by Larry Celona, Carroll Alvarado and Tina Moore