By Nicole Chavez, CNN

(CNN) -- The Walmart where El Paso's deadliest massacre unfolded is right in the center of the city and less than 3 miles north of the US-Mexico border.

It's often the first stop for hundreds of thousands of commuters from neighboring Ciudad Juárez, Mexico. And as many Mexican families who live hundreds of miles away south of the border also stop here during their monthly trips to El Paso.

If a gunman wanted to target Hispanics, the city of more than 680,0000 people would be an easy target. The majority of families here have Hispanic roots.

About 20 minutes before Saturday's shooting started, a post on the online message board 8chan believed to be from the suspect laid out a dark vision of America overrun by Hispanic immigrants. The 2,300-word document, which police called a "manifesto," was attached to a post that said, "I'm probably going to die today."

The day after, dozens of abandoned cars crowded the Walmart parking where a gunman unleashed terror and violence. It was eerily quiet as Texas state troopers guarded the crime scene on Sunday.

A safe city confronted with terror

This weekend's tragedy at Walmart has united El Paso's residents in an unprecedented way. They've waited hours at different blood banks across the city to donate blood to the wounded. Police officers have been flooded with food donations. And residents have prayed together in churches and parks across the city.

But even before the mass shooting that struck El Pasoans to their core, this Walmart was more than just a building.

Anyone who steps inside this Walmart can immediately tell it's in El Paso. Families are speaking as much in Spanish as in English. The parking lot is full of vehicles with Texas and Mexico license plates. The city's iconic landmark Star on the Mountain is within eyesight.

"It's a place where you can really feel that people are united," said Patricia Torres, 61, a regular customer and an employee at the adjacent Sam's Club store. "There are families from El Paso and of course from Ciudad Juárez but also from other places."

The Walmart is so beloved in the community that some of its employees have worked for decades at the store and won't leave even if they have to endure hectic commute everyday.

And it seems that the suspect targeted this place for that very reason.

Police say they believe that the 21-year-old white male suspect wrote a document posted online that rails against both immigrants and Hispanics. It blames immigrants and first-generation Americans for taking away jobs and for the blending of cultures in the US.

The suspect from Allen, a suburb of Dallas about a 650-mile drive away, is in police custody.

The mass shooting happened in one of the largest and safest cities on the US-Mexico border, a place central to the Trump administration's hardline stance on immigration and a city that state Rep. Cesar Blanco called "ground zero" of the administration's family separations policy.

For Jose Valadez, the owner of a small solar-energy company in El Paso, President Donald Trump's rhetoric against immigrants could have motivated the gunman -- a man with no clear ties to the El Paso-area.

"Trump is always labeling our culture as drug dealers and rapists. He's put fear in white Americans," Valadez said. "This (shooting) is what happens when you put fear in people."

The President has maintained the importance of securing the nation's borders during his administration. Earlier this year, he fought to close the US-Mexico border at El Paso and has pushed to enforce a stricter and more widespread family separations policy.

Trump called the El Paso shooting an "act of cowardice" on Saturday and said there "are no reasons or excuses that will ever justify killing people."

El Paso has been ranked among the safest metro cities in the nation year after year. Democratic presidential candidate Beto O'Rourke, an El Paso native, credits that distinction to the Hispanic origin of the El Paso population.

Speaking at a vigil Sunday night, O'Rourke said American cities can see El Paso as an answer to hatred and intolerance.

"One of the safest cities in the United States of America, not despite, but because nearly a quarter (people) who live in El Paso were born in another country," he said.

'We are American and Mexican'

Briyan Estrada and his friends stopped numerous times near Walmart to hand out ice-cold water bottles on Sunday. In the back of their silver pickup truck, a couple of American and Mexican flags were waving.

"We are doing this to show that El Paso is love. We are all united," said Estrada, a 21-year-old electrician.

The connection between the two countries is so palpable that experts say that shutting down the US-Mexico border could destabilize El Paso and Juarez, result in billions of dollars in economic losses, and could leave hundreds of Americans in exile.

Most El Pasoans have a connection with Juarez. Many grew up across the border, work or still live there. They also visit relatives every weekend and prefer to do their grocery shopping there.

Anahi Holguin, 21, one of Estrada's friends, says residents in El Paso are not afraid of constantly embracing that connection.

"We are proud of where we come from and this is la frontera (border). We are American and Mexicans," Holguin said.

"And Mexican Americans, all mixed together," Estrada quickly jumped to add.

El Paso doesn't want to be defined by murder

The Texas and American flags at the MacArthur School in El Paso, Texas, fluttered at half-staff Sunday morning as two women hugged each other crying after learning that their loved one was killed.

By dawn, dozens of people stood in silence along a growing memorial of flowers, candles and balloons overlooking the Walmart parking lot.

"Forever 915 Proud" and "El Paso Strong. Together as one," signs read. Another sign read, "As one we can overcome."

O'Rourke says El Paso will not be defined by the number of murders and that America can see this community as an example.

"Our differences are not dangerous, they do not define us, they will not divide us," he said.

Valadez returned to his car after visiting the makeshift memorial and met the trio of friends giving away water bottles. Shortly, they began talking like long-time friends. They spoke about families and how El Paso and Juarez have been their home for generations.

"Nothing is going to change El Paso," Valadez said as he was getting ready to drive off. "Nothing has ever done it in the past."