“There’s a shooting in the village from the gate!” he texted after militants fired at his car as he drove past the main entrance. Attackers later blew open a pedestrian gate nearby with explosives and flooded into the kibbutz.

Kaplan rushed home to grab his armored vest, helmet and M16 rifle, then drove off to check another gate on the northwest corner. There he found armed men were already inside the razor-wire security fence that encircled the community.

“Terrorists in the kibbutz! Terrorists in the kibbutz!” he yelled in a second, panicked voice text, begging his men to hurry. Gunshots sounded in the background. He had trained a dozen men for this moment, a surprise attack from nearby Gaza. Yet 19 minutes after his first alert, none had arrived.

Kaplan left his car and shot at assailants from behind a metal garbage container. One lobbed a hand grenade at him. In a stroke of luck for him and Mefalsim, it didn’t explode.

More than two dozen Hamas fighters from Gaza had arrived with orders to subdue the small security force and herd hostages into the community dining hall. They carried a detailed map of the kibbutz and, like other assault teams in southern Israel that morning, an attack plan labeled “top secret.”

Mefalsim was one place that day where nothing for the Hamas attackers went according to plan.

Soon after Kaplan’s call for help, his volunteers rushed from their homes in helmets and protective vests worn over the T-shirts they had slept in, toting M16 rifles. Outnumbered and fighting alone or in pairs, the men mounted a life-or-death stand, communicating via walkie-talkie and WhatsApp texts to track the militants and send each other help.

They believed they had to hold off the insurgents long enough for the Israeli army to arrive. At first, they hoped the soldiers would be there quickly. But as minutes passed, and the fighting grew worse, they realized they would have to fight alone.

“Where are the tanks?” Yarden Reskin, a 38-year-old landscape architect and security volunteer yelled into his walkie-talkie as the bullets flew. “It became very, very apparent that they weren’t coming,” he said later.

Yarden Reskin, a landscape architect and volunteer in Mefalsim’s volunteer security force. PHOTO: MAYA LEVIN FOR THE WALL STREET JOURNAL

Palestinian gunmen who flooded out of Gaza killed 1,400 Israelis and took close to 200 hostages, terrorizing and shooting people at more than 20 Israeli towns and military bases and thousands at an all-night music festival not far from Mefalsim.

In town after town, attackers blasted through security fences that encircled Israeli villages near Gaza, gunning down residents, burning houses with families inside and taking hostages.

Bodies and the burned-up cars of people fleeing the music festival, an early target, were later found outside Mefalsim’s main gate.

Frightened families at the kibbutz,a 200-acre, close-knit community with farm fields and tree-lined streets, took refuge in home shelters, some watching accounts of assaults in nearby towns on phones and TVs. They heard heavy gunfire just outside.

“We didn’t know what all the shooting meant,” said Gil Levi, 17, who was home with her mother, Inbal, younger brother Noam Levi and boyfriend, Ofir Itamari. Her father, Eli Levi, had told them not to come out of the shelter, no matter what.

He was in the living room standing watch through the plate-glass window, facing the southern fence of the kibbutz and the fields that stretched beyond.

When Levi saw militants heading toward the fence, he shot his M16 through the window. All his family could hear inside the shelter was the sound of gunfire.

“Were the terrorists inside the house?” Gil Levi recalled thinking.

Gil’s boyfriend handed her a souvenir Japanese knife he had found in the shelter and a pair of scissors to her mother, in case they had to fight off the intruders themselves.

The night before the attack on Mefalsim, around 30 families had spent the night camping in an olive grove outside the gate. It was an annual community outing on the last night of the Jewish holiday of Sukkot.

In the morning, around 6:30 a.m., sirens warned of incoming rockets from Gaza, a wail so common in local communities that even children treated it as routine.

When Shaked Porat, 43, heard the sirens at the campsite, he roused his two sleeping children—a 10-year-old daughter and 6-year-old son—and quickly drove home, entering through a back gate. At home, the children joined Porat’s wife and their 12-year-old son in the family’s shelter. Porat listened to the urgent voice text from Kaplan about gunmen at the northwest gate. His phone showed the battery at 10%.

Sunset at a campsite outside of the Mefalsim kibbutz on the night before the Oct. 7 attack. PHOTO: DAVID ROSENBERG

Porat, an Israeli army veteran and one of the volunteers in Mefalsim’s security force, ran out his door with an M16 and hustled to a street lined with houses on one side and a kibbutz gate on the other. About 40 yards away, he saw four armed men in vests and black jeans.

Thinking he recognized one of them, he called out, “Sasi!” the Hebrew nickname of another member of the volunteer force. “Ta’al,” one of them responded, meaning “Come here” in Arabic. Porat realized they were militants and started shooting. Two of the armed men ran toward nearby houses for cover. Two others hid behind a parked car.

Porat, who had been in firefights as a soldier, ducked into a small concrete enclosure for trash cans. “It’s a very lonely feeling,” he said later, “especially when you are one against four.”

A resident who watched the exchange of gunfire from an upstairs window yelled a warning to Porat: “They are throwing grenades!” Porat ducked and escaped injury. When one of the militants ran from a yard into the open, Porat shot him.

Shaked Porat, an Israeli army veteran and a member of volunteer security force. PHOTO: MAYA LEVIN FOR THE WALL STREET JOURNAL

A second attacker raised his head from behind the car, and Porat said he shot him, too. He saw a third gunman running away. The fourth attacker disappeared, said Porat, who stayed put for the next hour, guarding the kibbutz gate to keep out any others.

Photos taken later showed two dead men, one on the sidewalk and one in the street.

Video from a security camera at the main gate of Mefalsim captured some of the carnage that took place outside the main gate of the kibbutz as people fled the outdoor music festival and tried desperately to get inside, pursued by militants. A man in a white shirt was shot as he ran toward the entrance. He grabbed his right arm and dropped to the pavement, blood spilling from around his head.

Armed fighters emerged from a wooded area minutes later. Several ran to the fallen man and shot him again. Drivers who abandoned cars to hide in the bushes were attacked with grenades. A person pulled from the bushes was shot and bludgeoned with a rifle butt. The video was posted by South First Responders, a group of emergency personnel working in southern Israel, and verified by The Wall Street Journal.

The road where wreckage from the Hamas assault remains. PHOTO: DAVID ROSENBERG

After militants blew open the entrance at the kibbutz gate and streamed inside, Kaplan kept on the move, worried residents would leave their houses into danger.

“Someone send out a message to stay in the houses and not come out,” Kaplan said in a WhatsApp voice message, breathing heavily. “Emergency task force come to me! Emergency task force come to me! They are splitting up.” Shots cracked in the background.

Over the next hour, there were several gunfights. Security volunteers hunted for the militants who were moving alone and in pairs on residential streets. Two attackers were killed in the garden of a house by four Israeli soldiers who were home on a weekend leave. Two of the soldiers suffered minor wounds from grenade fragments.

Reskin, the landscape architect, came within sight of the main gate and saw a large group of attackers exchanging what looked like congratulations. He fired and they scattered. He next went into a nearby residential neighborhood and joined Idan Mayrovich, the team’s medic. As they walked, they saw Idan Kadosh, a resident, shooting with a handgun from his window, and he joined their patrol.

Two militants walked in front of an elderly woman’s house with their rifles on their shoulders, one holding a stolen children’s bike. Before the attackers saw the three defenders, Reskin fired and they ran.

A militant driving a stolen forklift was headed for the main gate, apparently intending to stack cars there and block an expected counterattack by the Israeli army. Reskin said he shot at the forklift, and the driver abandoned the vehicle.

Another group of militants made their way to a dormitory for foreign workers employed in the kibbutz’s farm operations. A dozen Thai workers hiding there were loaded at gunpoint onto a wagon pulled by a tractor that steered toward the front gate.

They were intercepted by the security volunteers. One of the kibbutz defenders shot at the wagon, and the militants fled, leaving the workers behind.

Almost an hour after the battle erupted by the front gate, the fighting shifted to Mefalsim’s southern perimeter.

David “Didi” Rosenberg, a member of the volunteer force, stood on his second-floor balcony where he kept watch on Mefalsim’s southeast fence, armed with his M16. His wife, who was in the home’s shelter with their two children, texted him, “I’m scared.” He suggested games to play with the kids.

Rosenberg, whose balcony overlooks the fence, reported over his walkie-talkie that a truck carrying a dozen armed men and a motorcycle ferrying two gunmen were roaring across an open field toward the fence.

David Rosenberg’s view of the fields where Hamas militants charged toward the perimeter fence. PHOTO: DAVID ROSENBERG

Levi, 48, the head of security and emergency management for Intel in Israel, had also been watching the southern perimeter through his living-room window, and he saw the attackers when they were about 100 yards away.

Levi, a former Israeli soldier, said he froze for a few seconds, thinking of the danger to his family. Then he heard Rosenberg, a few houses away, open fire, prompting Levi to start shooting at the attackers from his living-room window.

Noam Kazaz, 52, who had evacuated with his family to the house of another kibbutz resident shortly after his own was hit by a rocket, called Rosenberg. “We will die on the fence. No one is entering the kibbutz,” he recalled saying before he opened fire.

The three volunteers hadn’t trained to shoot at such a far range. But their heavy gunfire prompted the motorcycle driver to turn around. The men riding on the truck jumped off and flattened on the ground. Levi thought he could see several had been hit.

They kept shooting for the next 90 minutes—until Israeli soldiers arrived at Levi’s house. “I’m from the squad, I’m from the squad,” Levi yelled to the soldiers. “I’m an Israeli. Please don’t shoot me.” Then he went into the shelter and hugged his family. Instead of staying amid the shattered glass in their living room, they went to Rosenberg’s house for the comfort of being with neighbors.

Israeli soldiers spent the following three days going house to house, looking for any attackers who might be still hiding on the kibbutz. The bodies of eight militants were recovered, one resident said. Two more were killed after troops found them hiding in a cow shed. Another was captured, and the rest were driven off.

Evacuees from the Mefalsim kibbutz gathered for a meeting at the Dan Accadia hotel in Hertzlia, Israel. PHOTO: MAYA LEVIN FOR THE WALL STREET JOURNAL

No Mefalsim residents were killed or taken hostage, protected by a dozen residents, many of them former Israeli soldiers, who had prepared for years to defend the kibbutz.

Mefalsim also got lucky. Although the defenders didn’t know exactly how many attackers infiltrated the kibbutz, they estimated it was probably around 25 to 30, a group smaller than those that attacked other local communities, which suffered far more casualties.

Residents departed after the battle, many of themrelocating to a beachfront hotel north of Tel Aviv. Mefalsim has been declared a military zone and is closed. Most of the residents say they will return and rebuild their home.

“There is a feeling of discomfort that we survived, and others did not,” security chief Kaplan said.

But Mefalsim, at least, had survived.