Omitting the locking process, a single mistake led to an irreparable tragedy.
At 3:50 a.m. on November 26, 2025, a 1,300-ton automated stamping production line in the enterprise experienced a blockage fault. Maintenance worker Jiang entered the equipment to clean and debug the molds. According to national safety production regulations and the enterprise’s internal safety system, equipment maintenance must fully follow the LOTO Lockout tagout process: cutting off the main power supply, disconnecting the energy source, hanging warning labels, operating personnel installing personal safety locks alone, releasing the residual pressure of the equipment， and then conducting maintenance work.
However， the on-site team members generally had a fortunately mentality， only pressing the on-site emergency stop button,without disconnecting the main power supply,locking,hanging a maintenance warning sign,and not using any LOTO safety locks,extension lock hooks,or management lock station tools. The maintenance lasted for one hour,at 4：45 a.m.， production line supervisor Zhou reset the main emergency stop switch and verbally informed the operator to temporarily not start the equipment； due to the loud noise of the workshop machinery and the obstruction of on-site communication,the operator mistakenly judged that the maintenance was completed and directly closed the equipment safety door and started the stamping production line.
At this time， Jiang was still in the mold operation area of the machine tool. The equipment instantly closed the mold， generating a huge squeezing force. The maintenance personnel had no time to evacuate and suffered severe mechanical compression on the spot. After 120 on-site rescue， it was confirmed that they died despite efforts.
In-depth analysis:Four major LOTO management loopholes combined,and the safety defense line was completely lost.
The investigation team conducted on-site investigations,monitored video footage,and questioned personnel,sorting out multiple levels of violations in the accident,all pointing to the systematic failure of the enterprise’s LOTO Lockout tagout system：
Employees’ safety awareness was lacking,and they habitually omitted the core steps of LOTO.
The team had long formed the violation habit of “only pressing the emergency stop button,no LOTO tagout”. Maintenance personnel generally believed that cleaning the fault temporarily did not require the cumbersome locking process and did not know that the emergency stop switch only temporarily cut off the power supply， the main circuit was still energized,and there was a risk of accidental startup； the workshop did not set a standardized Management Lockout Station (centralized lock management station),safety lockers,multi-person extension lock hooks,and warning labels were randomly piled up,making it inconvenient for employees to access， further encouraging the violation of operation.
The enterprise’s LOTO management system was implemented on paper.
The enterprise had written energy isolation operation procedures,but it did not divide the exclusive locking points for each equipment,did not provide enough matching LOTO tools such as extension lock hooks,circuit breakers locks， and valve locks for stamping machines； there was no fixed lock storage workstation， the number of safety locks was insufficient,and there was no interlocking extension lock hook when multiple people were conducting maintenance,unable to achieve one-person-one-lock and joint locking.
Safety training and on-site supervision were completely absent.
The special LOTO training for new and old employees was just a formality,without actual practice of stopping – isolating – locking – verifying the electricity circuit. During night shift maintenance,no full-time safety supervisor was arranged， there was no unified maintenance confirmation mechanism among teams,and only verbal transmission of operation information was used,which was prone to information deviation.
Daily safety inspections did not check LOTO violation hazards.
The workshop safety inspection only focused on equipment capacity and never checked the implementation of locking in maintenance operations. For serious violations such as long-term unsecured maintenance and bypassing safety protection,they were not stopped or evaluated,and over time,a major safety blind spot was formed.
Post time: Jun-09-2026
