My player goes straight through my colider

So I'm making a 2D pizza delivering game and it has been going smoothly so far but I have run into my first issue. I'm using rigidbody2D. velocity controls so I get a continuously moving effect. But when I go over one of my buildings that has a box colider2d attached to it but my player just goes straight through the building without anything happening. This is my movement script. private void FixedUpdate() { //Player Movement if (Input.GetKeyDown(KeyCode.W) || Input.GetKeyDown(KeyCode.UpArrow)) { rb.velocity = new Vector2(0, speed); spriteRenderer.sprite = carUp; } if (Input.GetKeyDown(KeyCode.S) || Input.GetKeyDown(KeyCode.DownArrow)) { rb.velocity = new Vector2(0, -speed); spriteRenderer.sprite = carDown; } if (Input.GetKeyDown(KeyCode.D) || Input.GetKeyDown(KeyCode.RightArrow)) { rb.velocity = new Vector2(speed, 0); spriteRenderer.sprite = carRight; } if (Input.GetKeyDown(KeyCode.A) || Input.GetKeyDown(KeyCode.LeftArrow)) { rb.velocity = new Vector2(-speed, 0); spriteRenderer.sprite = carLeft; } if (Input.GetKeyDown(KeyCode.Space)) { rb.velocity = new Vector2(0, 0); spriteRenderer.sprite = carUp; } } I don't know any way of fixing this so any help would be very much apretiated. :)