All three if statements in a for loop triggering when only one is true (JavaScript)

This has me a little stumped. Whenever I execute this code, if one of the if statements in the for loop are true, all three sub-arrays of weaknessArray get effected. The same thing happens when each if statement is in it's own for loop and if instead of one 2D array I use a three separate arrays, one for each for loop.

var typeChart = [2,2,2,2,2,2,4,2,2,2,2,2,2,0,2,2,2,2];
var blankArray = [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0];
var weaknessArray = [blankArray,blankArray,blankArray];

for(i = 0; i<18; i++){
if(typeChart[i] === 0) weaknessArray[2][i] = 1;
if(typeChart[i] === 1) weaknessArray[1][i] = 1;
if(typeChart[i] === 4) weaknessArray[0][i] = 1;

console.log(weaknessArray);
}