Yaakov Yaakobov won't get to celebrate his son's bar mitzva next month. The father of two teenage boys died just before midnight in Beersheba's Soroka Medical Center after he was critically wounded Tuesday morning when a Palestinian-launched Kassam rocket hit the factory where he worked on the outskirts of Sderot. Four other workers were lightly wounded. "I saw him lying on the ground with blood on his face," his co-worker Tanya Basov told The Jerusalem Post. She was among the lucky factory workers who made it safely out of the building after the warning siren rang out around 8:30 a.m. A video released to the media showed how the workers ran for the safety of a nearby protected room. Yaakobov, who immigrated from Russia 12 years ago, is the last one seen heading out from behind a stack of boxes before the Kassam crashed through the roof and the room filled with smoke from the fire that broke out upon impact. "People were still holding their hands to their ears because the noise had been so loud," Basov said as she sat in the factory's office across the way. As she spoke, workers cleared away the burnt timber from the factory. On a table to the side, the half-filled coffee and teacups were still where some workers had left them. They had been on break at the time of the explosion. It's the second attack on the city with serious casualties in less than a week. Last Wednesday, a Kassam rocket killed Sderot resident Fatima Slutsker. Tuesday's attack on the factory occurred as the UN High Commissioner for Human Rights Louise Arbour was on a planned visit to the city as part of her five-day trip to the region. On Monday, she visited Beit Hanun, the city from which many of the Kassams are launched and which has been the target of IDF retaliatory operations. UN spokesman Christopher Gunness said that upon their arrival in Sderot, two Kassams landed some 200 meters from their car as they were parked on the side of the road. They continued to the mayor's office and were meeting with him when the factory was attacked. Arbour asked to be taken to the scene and Sderot Mayor Eli Moyal later told the Post he was only too happy to oblige. According to Gunnes, Arbour condemned the attack and said, "Kassam rockets are illegal under international law because they are too inaccurate to distinguish between civilian and non-civilian targets." In addition, Arbour said that Israel "has a responsibility to defend its citizens, but has to do so only by legal means. It has to do so in line with international law, including international humanitarian law, but it has a primary responsibility to protect people who are under its authority." While Moyal said he was pleased by Arbour's visit, not everyone was happy to see her. According to footage of the scene, a few workers at the site of the rocket attack shouted some curses at her and one threw a stone at her vehicle as it drove away. Gunness downplayed the significance of the attack on the high commissioner. He said she was well received and a welcomed guest in the city during her two-hour tour which included a visit to a kindergarten class. Arbour also got a first-hand look at the way Kassam attacks induce panic in children when a warning siren rang out while she was in the classroom. In light of the barrage of Kassam attacks in the last week, the city had asked that only those schools which had been reinforced against attacks be opened. Some 25 percent of schools are still unprotected. Moyal said that only about 40 percent of the children showed up to school on Tuesday. Sitting smoking in his office, Moyal said, that he was doing his best to hold onto a semblance of normality given the unrelenting barrage of rockets against his city. "Our answer to terror is routine, routine, routine," he said. Across the city, outside of the ammonia factory, Marietta Davidovitch said she had no choice but to live by that same motto. She continued to work in the factory's office on Tuesday, even though she heard about the attack on her way in to work. "My son has already called twice today to see how I am doing," she said. An immigrant from Romania, she said that, in spite of her fear, she had no intention of leaving the city. "Where would I go?" she asked. AP contributed to this report.