Access violation when writing two dimensional vectors

My program keeps on crashing when x = 2 and y = 6 cellChargeTime[x][y].push_back(0); Any ideas on how to fix this or what might be causing this crash.

vector<int> **cellChargeTime;

cellChargeTime = new vector<int>*[xMax]; //xMax = 40
for (int x=0; x<xMax; x++)
    cellChargeTime[x] = new vector<int> [yMax]; //yMax = 40

for (int x=0; x<xMax; x++){
    for (int y=0; y<yMax; y++){
        for (int i=0; i< numRuns; i++){ //numRuns = 1
            cellChargeTime[x][y].push_back(0); // Crashes at x = 2; y = 6
        }
    }
}