On Thursday, 3 September 2026, at around 10.10 local time, a fire broke out in a factory building of an oleochemical processing company in the Sei Mangkei Special Economic Zone, Simalungun Regency, North Sumatra. Three workers died (iNews, 2026). The Ministry of Industry expressed its condolences, noted that the plant had only started operating in July 2026, and said it was coordinating with the zone operator, the company, the police and local agencies to ensure a thorough evaluation (Fiansyah, 2026).
At the time of writing, the police are still investigating the cause and no official investigation report is available. The questions below use only reported facts and draw lessons from the applicable fire prevention framework, not from guesses about the cause.
What Is Known?
According to police quoted in the press, the three victims were welding helpers working for a construction vendor. They were doing final weld repairs on the sixth floor and had reportedly worked at the site for only four days. The fire is thought to have started on the third or fourth floor, and people nearby heard a loud bang (iNews, 2026). One early report said the victims were thought to have jumped from the fourth floor (Febiari, 2026), while the Bernama news agency reported that they jumped from the sixth floor when flames and smoke reached their work area (Bernama, 2026). Such differences are normal in the first hours and can only be settled by the investigation.
Firefighting involved 13 fire units, with support from the police mobile brigade, the army and the regency government (Febiari, 2026), and crews were still fighting the fire more than three hours later (Bernama, 2026).
Was Welding the Cause?
That cannot be concluded. The fact that welding was under way in the building does not explain where the fire started, especially since it is thought to have begun on a different floor from where the workers were (iNews, 2026). In our understanding, a sound fire investigation tests every possible ignition source, including electrical equipment, the process and hot work, against physical evidence before ruling it in or out.
What can be said is that hot work is routinely controlled through a written permit. A study of hot work permits for tank welding in Balikpapan found 90.9 percent conformity with the applicable standard, with shortfalls in personal protective equipment compliance and the use of welding habitats (Lim et al., 2025). The figure comes from one site, but it shows that a permit system that looks good on paper can still leave gaps in the field.
Why Upper Floors?
This is our interpretation, not an investigation finding. Workers several floors above the point of origin have to pass a burning or smoke-filled floor on the way down unless a protected stair is available. Workers who have been in a building for only a few days may not know where the alternative stairs or the assembly point are. In those conditions, split-second decisions are made without a safe option. The planning question is simple but rarely tested: from each work point on an upper floor, how long does it take to reach a protected stair, and is that time still available when a fire starts on a floor below?
What Must Employers Do?
Minister of Manpower Decree KEP.186/MEN/1999 requires employers to prevent, reduce and extinguish fires. Article 2 sets out what that means: controlling every form of energy, providing detection, alarm, extinguishing and evacuation means, controlling the spread of smoke, heat and gas, forming a fire response unit, holding regular drills, and keeping a fire emergency plan for workplaces with more than 50 workers or with a medium or high fire hazard. Article 6 requires at least 2 fire wardens for every 25 workers (Menteri Tenaga Kerja Republik Indonesia, 1999).
What About Contract Workers?
These duties cover everyone in the workplace, including vendor workers. The Ministry of Industry itself said it pays serious attention to the safety of workers in industrial zones (Fiansyah, 2026). In our view, the most dangerous period is the first few days, when contract workers do not yet know the building, its alarms or its exits, while their work often takes place in areas that are still changing because of construction or repair.
What Should Plants Check?
- Does every hot work permit name the escape route and the fire watch for the area, including the floors above and below?
- Do multi-storey buildings still being finished have usable emergency stairs, free of stored material?
- Does contractor induction include walking the actual exit routes, not just a verbal briefing?
- Can the alarm be heard on every floor, including areas where contractors are working?
- Do evacuation drills include contract workers on duty?
Nusa Safety helps companies assess their fire and emergency readiness. The Fire and Emergency Safety Audit (FESA) checks protection systems, escape routes and emergency plans against the risks of the building. Emergency Preparedness Drills train both employees and contractors, and the HSE and CSMS Audit assesses contractor controls, including induction and work permits. Nusa Safety issues internal training certificates only.
This article is general information and not legal or professional advice for any specific case.
References
- Bernama. (2026, September 4). Three killed after jumping from burning factory in Indonesia. New Straits Times. https://www.nst.com.my/amp/world/region/2026/09/1525288/three-killed-after-jumping-burning-factory-indonesia
- Febiari, S. (2026, September 3). Kebakaran pabrik sabun di Simalungun, 3 tewas [Soap factory fire in Simalungun, 3 dead]. Metrotvnews.com. https://www.metrotvnews.com/read/N9nCyp4A-kebakaran-pabrik-sabun-di-simalungun-3-tewas
- Fiansyah, R. (2026, September 5). Pabrik Evyap di Sei Mangkei kebakaran, Kemenperin ingatkan pentingnya keselamatan kerja [Fire at a Sei Mangkei factory; industry ministry stresses workplace safety]. IDX Channel. https://www.idxchannel.com/economics/pabrik-evyap-di-sei-mangkei-kebakaran-kemenperin-ingatkan-pentingnya-keselamatan-kerja
- iNews. (2026, September 3). Identitas 3 korban tewas kebakaran pabrik di KEK Sei Mangkei, baru 4 hari bekerja [Three victims of the Sei Mangkei factory fire identified, had worked four days]. RCTI+. https://www.rctiplus.com/news/detail/nasional/5465380/identitas-3-korban-tewas-kebakaran-pabrik-di-kek-sei-mangkei--baru-4-hari-bekerja
- Lim, F. K. L., Rusba, K., & Nur, M. (2025). Analisis penerapan surat izin kerja aman hot work pada pekerjaan pengelasan di tangki O9 di PT. XYZ Balikpapan [Implementation of hot work permits for welding on tank O9 at PT XYZ Balikpapan]. Identifikasi, 11(3), 529-536. https://doi.org/10.36277/identifikasi.v11i3.676
- Menteri Tenaga Kerja Republik Indonesia. (1999). Keputusan Menteri Tenaga Kerja Nomor KEP.186/MEN/1999 tentang Unit Penanggulangan Kebakaran di Tempat Kerja [Minister of Manpower Decree KEP.186/MEN/1999 on workplace fire response units]. https://jdih.kemnaker.go.id/asset/data_puu/1999kmnaker186.pdf
