C++: Array within Tuple within Vector gets replaced with last entered

Question

Here is a Minimal Reproducible Example:

#include <iostream>
#include <vector>
#include <tuple>
using namespace std;


int main() {

    vector<tuple<char *, int, int>> test;
    cout << "During Loop:" << endl;
    for (int i = 0; i < 4; i++) {
        char letters[3];
        int firstNumber = i;
        int secondNumber = 4 - i;
        switch (i) {
        case 0:
            letters[0] = 'a';
            letters[1] = 'b';
            letters[2] = 'c';
            break;
        case 1:
            letters[0] = 'd';
            letters[1] = 'e';
            letters[2] = 'f';
            break;
        case 2:
            letters[0] = 'g';
            letters[1] = 'h';
            letters[2] = 'i';
            break;
        case 3:
            letters[0] = 'j';
            letters[1] = 'k';
            letters[2] = 'l';
            break;
        }
        tuple<char *, int, int> toPlace = make_tuple(letters, firstNumber, secondNumber);
        test.emplace_back(toPlace);
        for (int j = 0; j < 3; j++) {
            cout << get<0>(toPlace)[j];
        }
        cout << " " << firstNumber << " " << secondNumber << endl;
    }

    cout << endl << "After Loop: " << endl;

    for (int k = 0; k < 4; k++) {
        for (int l = 0; l < 3; l++) {
            cout << get<0>(test[k])[l];
        }
        cout << " " << get<1>(test[k]) << " " << get<2>(test[k]) << endl;
    }

    return 0;
}

This is the output:

During Loop:
abc 0 4
def 1 3
ghi 2 2
jkl 3 1

After Loop:
jkl 0 4
jkl 1 3
jkl 2 2
jkl 3 1

So why do the arrays within the tuple all become 'jkl', whilst the numbers do not change? (Using a string doesn't have this issue I know I could just use that, but I'm curious as to why this happens, as it also happens if the array is of type int).

I'm assuming it is because when making the tuple, its passing by reference into that make_tuple function and that points to the 'letters' array which get changed each loop. If so how would I rewrite this so an Array value could be stored in the Tuple rather than the pointer each time?

TL;DR: I tried to store a vector of tuples in which one is an array, by entering the tuples through a loop. During the loop it store the correct char array, and I was expecting the tuple would keep the value of the char array as it was entered. However it ends up replacing each char array with the last one entered, as it is actually a pointer that has been entered.