A transformer explosion sent a two-story jet of flame into the air on Newbury Street at about 12:15 a.m. this morning, blowing out the windows of Allston Beat. No one was harmed in the explosion.

‘There were fifteen-foot flames coming out of the ground,’ said Sonsie Restaurant valet Timothy Daluz. ‘I felt it before I heard it; I was two feet away.’

An above-ground transformer exploded Wednesday morning, causing power outages along Commonwealth Avenue in Brighton for about an hour.

NSTAR workers at the scene said they did not know what caused the transformer, set underneath the sidewalk in front of Allston Beat, to explode. As the area leading down to the transformer filled with water, workers still did not know the source of the explosion, or its full consequences.

‘Until we get down there, we won’t know what happened,’ one worker said.

Josh King, another valet at Sonsie, said the explosion looked like a ‘mushroom cloud.’

‘It was like the towering inferno,’ he joked.

Daluz initially had a more serious reaction.

‘I thought it was like a motorcycle bomb,’ he said. ‘I saw people running away and I didn’t know what was going on.

‘The way everything is on the news nowadays, you first think something’s negative.’