The BBC named the pub as the Clutha Vaults in Stockwell Street.
Murphy, a Labour frontbench MP who was in the area at the time, said members of the public formed a human chain to help get people out of the building.
Describing the aftermath of the incident as a “horrible scene”, he said dozens of fire officers as well as police were in the area.
“It seems like a helicopter crashed into the roof of this very busy pub. I was passing and just got out of my car to try to help people.”
He added: “What I saw was a pile of people clambering out of the pub, dust everywhere. People were covered in multiple injuries.”