An underground explosion in Salt Lake City is under investigation after traffic lights and power were knocked out near 300 South Main Street early Saturday.

The explosion was first reported at approximately 3:30 a.m., with witnesses saying they had seen multiple manhole covers blown from the street and fire coming from underground.

Salt Lake City Fire says the explosion emanated from electrical vaults operated by Rocky Mountain Power. Hazmat crews dispatched to the scene detected gases and “organic compounds that can sustain explosions” near the dislodged manhole covers. They didn’t not find any of the materials in any nearby buildings.

Power remains out along 400 South. UDOT crews are currently working to power traffic lights in the areas. Rocky Mountain Power is working to repair the damaged electrical equipment.

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