Damage after EV explosion caused by deactivated sprinkler system, fire authorities say

Severe fire damage following the explosion of a Mercedes electric vehicle in an underground parking lot in Incheon on Aug. 1 was likely due to the sprinkler system being turned off by management office staff, fire authorities say.

Cars left burnt in an underground parking lot in Incheon. A total of 140 cars were damaged in a fire caused by a Mercedes-Benz EV explosion on Thursday, and of them, 40 were completely burned. [NEWS1]

Severe fire damage following the explosion of a Mercedes electric vehicle in an underground parking lot in Incheon on Aug. 1 was likely due to the sprinkler system being turned off by management office staff, fire authorities say.

A preliminary investigation by the Incheon Fire Department revealed that the fire was detected by the receiver momentarily after the vehicle busted into flames at 6:09 a.m., but the pre-action valve, which controls the sprinkler system, was turned off from the apartment management office.

The sprinkler system will not activate despite receiving a fire alarm if the valve is deactivated.

The valve was un-paused five minutes later, at 6:14 a.m., but the fire had already affected the repeater in the system, resulting in the sprinkler system not responding to the fire, according to the Incheon Fire Department on Friday.

A pre-action fire sprinkler system works as in a two-step process where the detection of fire or smoke triggers the valve, releasing the water into the pipes and subsequently to the sprinkles — water is not stored in the sprinkler pipes under normal circumstances.

While a pre-action fire sprinkler system can help reduce water damage caused by fire alarms, the two-step process also slows down the reaction time.

The national fire agency plans to book the apartment staff without detention following further investigations. The Installation and Management of Firefighting Systems Act prohibits blocking or closing firefighting systems that can affect their performance. Violating the act can result in imprisonment of up to five years or a maximum fine of 50 million won ($36,195).

The Mercedes-Benz EQE electric vehicle exploded at an underground parking lot in an apartment in Incheon on Aug. 1. The car was first seen fuming white smoke, followed by an explosion. The EV was not plugged into the charger at the time of the blast.

BY CHO YONG-JUN [cho.yongjun1@joongang.co.kr]