The three mothers set out Monday morning in a caravan of SUVs, leaving their isolated religious hamlet in northern Mexico with 14 children in tow.

Wary of the drug cartels that patrol the region, families like theirs from the fundamentalist Mormon settlement of La Mora knew to travel by day to avoid danger. And they knew to travel together.

But the women had not ventured far when, for reasons that are still unclear, armed attackers descended on them. Gunmen sprayed one SUV with bullets, then set it on fire, killing one mother and her four children. A few miles east, gunmen opened fire on the other vehicles, killing the two other mothers and two more children. Several other children were injured and airlifted to a hospital.

In the broad but tightknit community of ultrareligious Mormons — where so many are related by blood, marriage and friendship — the violent deaths of the three women and their young children rippled out from La Mora to a sister community of Colonia LeBaron, and across the U.S.-Mexico border to North Dakota, Arizona and beyond.

Relatives and friends of the extended LeBaron family mourned the lives lost in an outpouring of social media posts and exchanges on the messaging service WhatsApp. Many changed their profile pictures to an image of a black ribbon inscribed with the text “Oremos por LeBaron-La Mora” — Let’s pray for LeBaron-La Mora.

Authorities have yet to determine who killed nine members of a Mormon family in Mexico on Nov. 4, or their motive, but the victims' family is demanding justice. (The Washington Post)

“I think we all woke up this morning hoping it was just a bad nightmare,” said Leah Staddon, who told The Post she was related to all three women. “We’re all still in shock that this happened.”

Relatives said the six children who died ranged in age from 8 months to 12 years. They identified the mothers as Rhonita Maria Miller, 30; Dawna Langford, 43; and Christina Langford Johnson, 30.

“All three of them were just the sweetest women,” Staddon said, “just beautiful mothers and wives and friends to the whole community.”

Even though their families were large, they still went out of their way to make time for each of their children, said Daniel LeBaron, a cousin of Miller.

“There are very, very dedicated mothers,” he told The Post. “They were super dedicated to their children, and [taught them] the value of hard work since they were young.”

At least nine members of a Mormon family were ambushed and killed by unknown gunmen on Nov. 4 in northern Mexico. (Kenneth Miller, Lafe Langford Jr via Reuters)

La Mora, where the families lived, is a roughly 1,000-acre ranch community in Mexico’s Sonora state made up of about 30 to 40 households, according to Staddon, whose extended family has lived there for more than 40 years. Many residents are dual citizens, she said.

Some of the families grow pecans, others are ranchers, and some bounce back and forth between Mexico and the United States for construction work, according to relatives.

“Our family’s real industrious,” said Kenny LeBaron, a cousin of Johnson who grew up in Mexico and now lives in North Dakota. “I don’t think there’s a single member of our family that’s 25 years old that doesn’t own a company.”

Staddon said she was born in La Mora and lived there until she was 19, when she moved to the United States. Growing up, she felt safe on the ranch, which she described as peaceful and quiet, with a river running through it. As a kid, she delighted in being around horses and other farm animals.

“It was just a kid’s paradise down there growing up,” said Staddon, who now lives in Arizona and visits the community a couple times a year.

But in recent years, the families have faced threats and violence from organized-crime groups vying for power in the region. In 2009, a prominent member of the clan, Benjamin LeBaron, 31, was shot dead in northern Mexico. He had publicly denounced the drug traffickers after they abducted his younger brother and demanded a $1 million ransom. (The family refused to pay.) The killers left a message saying they were retaliating for LeBaron’s activism.

“This has happened before in the past,” Kenny LeBaron said. “This isn’t our first run against the cartel.” He added that many in Mexico “accept it as part of reality.”

Staddon said that at some point, drug cartel members cut the community’s phone lines down, so her family relies on WhatsApp to exchange news.

She said the violence seems to have become worse in the last several months, with family members pulled over and threatened with guns.

“They said we would be okay as long as we didn’t travel at night,” Staddon told The Post. “Everybody made sure they were traveling in the daytime. But this happened yesterday in the middle of the day.”

It’s not clear exactly how the brutal assault unfolded. Lenzo Widmar, a community member who found two of the destroyed vehicles, said one of the women was driving to Arizona to pick up her husband from the Phoenix airport. The other two were going to accompany her as far as a main highway near the border, then head to a wedding nearby, he said.

Mexican officials said cartel gunmen might have mistaken the SUVs for those of rival traffickers. But relatives of the victims said the gunmen knew they were firing on civilians.

The deaths fell especially hard on Colonia LeBaron, La Mora’s sister community in neighboring Chihuahua state. Miller’s cousin Samuel LeBaron called it “the worst thing that’s ever happened here.”

“Every family is affected,” he said.

LeBaron said he had fond memories of watching football on Sundays with Miller and her husband, Howard, who would stop by whenever they stayed in town.

“She comes from a family of a lot of girls,” LeBaron recalled, “and she’s the sweetest of them all.”

Mary Beth Sheridan in Mexico City contributed to this report.