Populating a 2D array in Javascript with random numbers

I'm trying to populate a 2D array in javascript with random numbers. Although each column in the array is random, each row is identical which is not what I want (see image below). I want both rows and columns to be random.

http://eeldesigns.com/image.jpg

cols = 5;
rows = 10;

front = new Array(cols).fill(new Array(rows));

// Loop through Initial array to randomly place cells
for(var x = 0; x < cols; x++){
  for(var y = 0; y < rows; y++){
    front[x][y] = Math.floor(Math.random()*5);
  }
}
console.table(front) ;