The witness says the adrenaline was still pumping after the horrific attack.
The person is one of the many people who witnessed the attack inside Lynn Mall this afternoon.
A man was fatally shot by police officers and several shoppers were understood to have suffered life-threatening injuries in the supermarket attack.
Four people have been injured - two critically. They include people attacked in the supermarket. Their assailant was then fatally gunned down by police.
Three critical patients, and another in a serious condition, have been taken to Auckland City Hospital. One person in a moderate condition is at Waitākere Hospital, and another in a moderate condition is at Middlemore Hospital.
Chaos as police and paramedics rush to the scene
A man, who didn't wish to be named, filmed an injured woman being taken off a bus at New Lynn train station.
In the video, the woman appears to be bleeding from an injury near her left shoulder.
The man, who lives in an apartment overlooking the station, said more than seven police cars rushed to the scene just before 3pm.
They blocked both ends of the road near the station as three ambulances also arrived.
Police got onto the bus first, before paramedics joined them.
Shortly after they can be seen in the video carrying the woman off the bus. She is still conscious as they lay her onto a stretcher.
Another witness, who didn't want to be named, said they saw two people stabbed, a possible middle-aged Pākehā woman and an older man.
Moments later, the suspected perpetrator was shot by what looked like two undercover cops and fell to the ground.
The witness said customers then rushed to shelter in the aisles.
"So sad, I'm still shaking from what happened, just about to go in, and saw people running out. Imagined those who were already inside and saw the incident. Keep safe families," one person commented on the Herald Facebook page.
'He had a knife, a pretty big knife - like I would say the size of his arm'
A 34-year-old local man witnessed the beginning of the attack in New Lynn Countdown which he said occurred about 2.40pm.
The witness said he had been in the store for about 10 minutes and was in the dairy section in one corner of the supermarket.
"It literally happened in front of me. I was just buying stuff and walking toward the milk aisle, and then suddenly I heard a person shouting loudly 'Allah hu Akbar' and just running.
So there was this lady in front of me and he jumped on her so she fell, so that person [the attacker] also sort of lost his balance. He also fell. Then he got up. But I was behind so I couldn't see his face but this person was wearing like a khaki jacket and he had a knife, a pretty big knife - like I would say the size of his arm. It was very scary. It was like a mini sword, not like a full sword. It was like a sword literally.
The 34-year-old witness said he wasn't sure if the woman who was jumped on got stabbed.
"She could have been. She was lying on the floor. I have a feeling she may have got stabbed," he said.
The witness said he didn't see the attacker's face as he was behind him.
"It was four or five steps away from me, and I had a clear path to run so I ran," he said.
"He [attacker] wasn't tall, I think he was about 5'8 or something. Slightly hefty guy. Then that lady fell and he went to the other side shouting 'Allah hu Akbar' and then I ran out. I was one of the first people, because I was right there. So I started telling people there was someone with a knife, 'come out, come out'. They didn't believe at the beginning because it was right in the corner of the store. Near the dairy section.
"One of the Countdown ladies started running outside, and then [others realised] this is real.
"At the beginning I thought it was a prank. Someone wanted to scare people and create some problem. Later I realised it was real so [I] started running outside shouting at people to come out."
"People by then had started coming out, people were scared, a few people fell down.
"The worst part was when I was entering I was looking at people who were standing in the [supermarket] queue. Most of them were aged people when I was entering. There were at least seven or eight elderly people I would say, 55, 60 years old."
"Suddenly there were like four people who looked like undercover cops, I don't know. They were there, they knew something was happening, immediately, within a few minutes, and then they went inside.
"While people were coming out I could see one lady wearing a white T-shirt completely bleeding and really panicking. People were trying to help her.
"We didn't know if this person carrying a knife had a gun, or a bomb, we didn't know. It was very scary so people started running out and all the cops started coming in.
"I saw another person bleeding from the shoulder really bad."