An underground explosion in Grass Valley Tuesday evening causes Colfax Avenue to be closed. Right around 5:30 a call came into dispatch of an explosion strong enough to lift a manhole cover had just occurred. Nevada County Consolidated Division Chief Jerry Funk tells KNCO fire crews responded immediately.
According to Chief Funk, initial air monitoring showed no unsafe levels of gas in the system.
Colfax Avenue was closed for several hours from the bowling alley to the turn at the softball fields while the system was checked and cleared. The cause had yet to be determined at 7:45 PM.