For eight years, Amin Abdullah guarded the Islamic Centre of San Diego.
On Monday, the father of eight was the only person standing between two heavily armed teenagers and 140 children inside.
He opened fire as they tried to storm the entrance, delaying the attackers long enough to warn the teachers to lock the classroom doors of the mosque’s school.
He was killed along with two community members during the attack, which is being investigated as a hate crime.
The suspects reportedly left Nazi stickers and anti-Islam hate messages at the scene and in their car.
The writings included references to Brenton Tarrant, who killed 51 people in Christchurch in 2019. The San Diego gunmen referred to themselves as the “Sons Of Tarrant”.
Although a motive for the attack has not been made clear, police said they believed the teenagers had been “radicalised online” and that a “manifesto” had been found at the scene.
Scott Wahl, the San Diego police chief, said the security guard’s actions “without a doubt, delayed, distracted and ultimately deterred these two individuals from gaining access to the greater areas of the mosque”.
Taha Hassane, the imam and director of the centre, said: “If it was not for him... the carnage would be much worse. He’s the one who stopped them, who slowed them down... he sacrificed his life.
“We’re so proud of him ... Our entire community misses him.”
A fundraiser for Abdullah’s family has raised nearly US$2 million ($3.431m) in less than 24 hours.
When the shooters looked for people to target inside the mosque, police said the two other victims – Mansour Kaziha, manager of the mosque store for 40 years, and his friend Nader Awad – drew their attention to the carpark where they were shot and killed.
Wahl said: “I truly believe their actions saved the 140 kids inside”.
Dozens of children had managed to run and hide in a cupboard inside the complex as shots rang out around them.
Hassane called all three victims “our martyrs and our heroes”, adding: “The lives of the kids were saved. The lives of everyone in the school were saved, and we’re so grateful for that”.
The shooters, identified as Cain Clark, 17 – a home-schooled wrestler – and Caleb Vazquez, 18, fled the scene before killing themselves in a car parked nearby.
Authorities have declined to provide details of a possible motive, but said they found evidence that the gunmen shared a “broad hatred” of different religions and races.
The pair left anti-Islam writings, a weapon adorned with hate messages and a petrol can with “SS”, which appeared to refer to the Nazi paramilitary organisation.
On Tuesday, Mark Remily, an FBI special agent, said that one of the gunmen left behind a manifesto, but did not reveal its contents.
He said: “They did not discriminate who they hated, it covered a wide aspect of races and religions”.
Remily said it was too early to determine whether the Islamic Centre was the specific target, adding: “They definitely had a broad hatred of a lot of folks”.
He added that officers found 30 guns and a crossbow at three locations related to the gunmen.
None of the weapons were registered to the teenagers, and the ones used in the shooting belonged to one of their parents.
Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.