premise: Steam or smoke is seen pouring from the open manhole in Old Street in a shocking video taken at the scene. A pile of rubble is by the manhole cover as shocked witnesses gather at the scene. One person can be heard saying: “It exploded!” Another can be says: “What the f**k! Oh my God.” A third said: “That was scary. Did anyone get hurt?”
hypothesis: There were 4 witnesses
reason: There were at least three witnesses, but there may have been more. 