The explosion at a Northridge power plant that left 140,000 customers across the San Fernando Valley without electricity last weekend was a major blow to Los Angeles’ power grid.
It marked the first time in 12 years a Department of Water and Power receiving station was knocked offline. And it left a large swath of the Valley without power, in some cases for 12 hours, during one of the hottest days of the year.
On Monday, officials said the explosion was probably related to excessive energy demands due to the heat wave and was a stark reminder of the challenge Los Angeles faces in modernizing its aging electrical system.
DWP General Manager David Wright called the incident “highly unusual.” The exact cause of the blaze is under investigation, but Wright said it’s believed mineral oil being used as a cooling agent caught on fire and caused the transformer to explode.
The size of a large truck, the high-voltage transformer that was destroyed was more than 40 years old and would have probably been replaced in the next to five to ten years, Wright said. Recent testing of the device showed no problems, he said.
As inspectors assess the damage and investigate what caused the explosion, Saturday’s incident is emblematic of the challenges facing the nation’s largest municipal utility as it plays catch-up to update its aging power grid, officials said. The blast provided another example of the city's deteriorating infrastructure, which has made headlines after epic bursts of aging water pipes, crumbling sidewalks and gaping sinkholes.