### Clue: Shooting up and hitting the wall (9)
### Answer: EXPLODING 
 ### Explanation: Definition: Shooting up,hitting the wall
 Double defn: 1st: …/rapidly increasing in extent or intensity; and 2nd: Going up/hitting? the wall/becoming very furious/angry.
I'm not sure of the 2nd, as "hit the wall" is when an athlete suddenly becomes exhausted in a long race, different from "go up the wall".