Gamal Fouda was about five minutes into delivering his sermon from his elevated pulpit to 200 worshippers when some of them started jumping and shouting after what sounded like three gunshots.
He wondered if it was some of the youngsters playing around or noise coming from the sound system, the Al Noor Mosque imam tearfully told the Herald in his first interview since Friday afternoon's terror attack.
But then another shot was fired, this time closer, and an Algerian man yelled, "Yeah. Shooting!" before he smashed a window.
"Then the shooting started heavily," said Fouda, who ducked down and hid from the diminutive figure wearing a helmet, glasses, and military-style clothing and firing a semi-automatic weapon.
"People ran towards the big hole [in the glass]. Most of the people, they run through the window. That's why on this right side [of the building] only a few people were killed. But the left side, they fell on each other and they piled on top of each other. He was just standing and aiming at them."
The gunman methodically moved through the building executing people.
"Whenever he heard any noise coming from anywhere he would shoot towards it," Fouda said.
"He kept guarding people, calmly, and he was shooting and shooting and shooting and shooting.
"We couldn't even breathe from the smoke and the bullets flying everywhere.
"When he would run out of bullets, we were not sure if he had left because there was silence.
"We thought he was hiding, waiting... we were not able to see him. And thanks to God he did not know where we were.
"He came back and he started shooting again. Those people who came out from [hiding], he shot them again. Because we didn't know he was coming back."
The killer also sprayed bullets into the piles of bodies, Fouda said.
Many who escaped hid in the mosque's rear carpark while others jumped fences to safety.
One person who was trying to phone 111 was spotted by the gunman and shot.
Fouda hid with others in the main mosque room throughout the shooting which left 43 people dead at his mosque.
He assumes the shooter didn't know that the women were hiding in a separate room, saving their lives. Some women who tried to flee were gunned down.
"Still I can't believe that I am alive," Fouda said.
When the gunman finally left, to jump back into his car and race across the city to attack the Linwood Mosque - where seven were killed by the same lone gunman - an Iraqi worshipper said he'd gone. Only then did the survivors emerge.
Fouda, Egyptian-born and trained, spoke to the Herald today alongside fellow Christchurch imam Alabi Lateef Zirullah, who survived the Linwood Mosque massacre.
At Linwood, there were about 80 worshippers, said Zirullah, a prayer leader.
The killer started shooting outside the mosque about 1.55pm, gunning down a man and wife outside.
Zirullah was inside when the shooting started.
"When I saw those Muslims shot dead I just told our brothers, 'Go down! Go down! Somebody has just shot our brothers outside the masjid'," Zirullah said.
"No one listened to me until unfortunately he came from behind and he shot one of our brothers [in] the head through the window. He saw him standing and shot him [through] the window. When glass got broken and the brother fell down, everyone realised to go down."
Zirullah rushed outside, along with fellow worshipper Abdul Aziz, who picked up a credit card machine, yelling "come here".
The gunman ran back to his car to get another gun and Aziz hurled the credit card machine at him.
The gunman returned firing and as Zirullah tried to lock the main door to keep the worshippers inside safe, Aziz, whose two children aged 11 and 5 were still inside, weaved through parked cars as the gunman fired shots at him.
Aziz then spotted the gunman's discarded gun, picked it up and squeezed the trigger but it was empty.
The gunman ran back to the car for a second time, likely to grab yet another weapon.
"He gets into his car and I just got the gun and threw it on his window like an arrow and blasted his window," Aziz said.
The windshield shattered: "That's why he got scared."
He said the gunman was cursing at him, yelling that he was going to kill them all. But he drove away and Aziz said he chased the car down the street to a red light, before it made a U-turn and sped away. Online videos indicate police officers managed to force the car from the road and drag out the suspect soon after.
Zirullah then started calling emergency services and tried to help the dying and wounded.
He said he had been prepared to die to save his people.
"I can't believe… I thought I'd be gone. I was ready to die because I felt for the brothers," he told the Herald.
The two leaders have been in a state of shock since the shootings, which have claimed 50 lives. A dozen people are in a critical condition.
Both men described the shooter as criminal who deserves the highest punishment allowed under New Zealand law.
Fouda has had just three hours of sleep since the attack.
His priority now is trying to get a final list of the dead and organise their funerals.
"It may take time – a long time – and we'll need lots of people to be involved in this," Fouda said.
"There is a plan in place and lots of people are giving support to the families affected whether they are injured or died. I ask them to stay calm and be patient.
"I myself when I walk in the street or I go somewhere, I try to hide myself because people … too many they want to ask questions and at the moment I just want to stay calm, to be able to help the community."
Fouda feels that those who have died - "May Allah give them peace" – have now passed into a better place, "to a world of justice, better than a world of injustice".
He broke down in tears when sending his condolences to his community.
"You are one family," Fouda said.
"I would like to send my sincere condolences to all New Zealanders. [Friday] was a war against all Muslims but I considerate it [a war] against all New Zealand and New Zealanders.
"We are not going to be scared. This is war against peace and we should put hands together. New Zealand is a peaceful country and we love it and we will continue to love New Zealand and New Zealanders. This shouldn't scare us or stop us from working together as brothers and sisters, friends, in this beautiful country."
Both Islamic leaders have urged their Muslim communities, and all fellow New Zealanders, to stand up against terrorism.