On Tuesday (June 24), the day of the New York primary elections, the temperature in New York City soared to a scorching 105 degrees Fahrenheit, with a heat index surpassing 110 degrees Fahrenheit. The sun blazed down mercilessly, making it unbearable for the residents, leading the city government to issue an extreme heat warning. At around 10:30 a.m., an underground transformer exploded in the Flushing central district on Main Street, accompanied by two loud bangs. Black smoke billowed from three manholes, causing sidewalk concrete slabs to be displaced by the powerful force. Bus stops and trash cans were toppled by the concrete slabs, fortunately without causing any injuries.
Ms. Wang, who runs a stall outside the Flushing Library, described hearing the two loud bangs around 10:30 a.m. She was startled by the dull sounds and saw black smoke rising from Main Street. The concrete ground opposite the Flushing Library also lifted, emitting a strong odor. She said, “The sudden loud noise made me think there was a war happening here!”
On-site, the police cordoned off a section of Main Street with caution tape, blocking traffic from 41st Avenue all the way to 41st Road, barring all vehicles from passing through. Repair vans from the power company Con Edison, police cars, and several fire trucks arrived to handle the situation. Public transport in the Flushing central district was temporarily disrupted, with some store power outages.
Three manholes on Main Street emitted black smoke, located in front of the “Ding Hao Pharmacy,” at the intersection of Main Street and 41st Avenue near the “Xingfu Tang” pharmacy, and at the junction of Main Street and 41st Road in front of the “Yi Li Su” fruit shop.
The manhole cover at the intersection of Main Street and 41st Avenue near the “Xingfu Tang” had previously emitted smoke due to high temperatures or rain. The explosion had a significant impact, as seen by a large concrete brick on the Main Street sidewalk opposite the “Ding Hao Pharmacy” being lifted. Bus stop signs and trash cans were also knocked over.
Under the manhole covers are electric and telecommunication facilities, such as cables and transformers. According to firefighters, high surface temperatures, combined with heavy electricity loads, can lead to overheating of underground transformers, sparking insulation oil or cable wrapping material, resulting in pressure buildup and causing explosions. Moreover, underground electrical equipment continually releases trace gases (such as methane, carbon monoxide, etc.) which can accumulate in enclosed spaces. If there is a spark or a rise in temperature, this could instantly trigger an explosion or fire.
The exploding pressure rapidly rises from underground and is released along the path of least resistance – typically through manhole covers or cracks in the surrounding floor, causing the floor to be blasted upwards. Black smoke emerging from the manholes usually indicates incomplete combustion, such as burnt plastic-coated cables or ignited insulating oil.
Due to the heat, as of 1 p.m. on the 24th, over 3,960 Consolidated Edison customers in the five boroughs of New York City experienced power outages. According to Consolidated Edison’s outage map, the highest number of outages occurred in Queens, affecting 2,235 households, followed by Brooklyn with 999, the Bronx with 666, and Staten Island with 67. Manhattan was the only borough that did not experience any power outages.
On the previous day (Monday), nearly 8,000 customers in Queens and over 7,000 customers in Staten Island were left without power. Consolidated Edison has urged residents of New York City to avoid using high-energy-consuming appliances such as washing machines, dryers, and microwave ovens. They have also requested residents to minimize unnecessary use of air conditioning units.