How can I conditionally load images in Svelte?

I am trying to create a webpage where you get a random image when you open the page. I want svelte to decide on a random image when the page loads and then load that image in the “src” tag. I have a set number of images that I will choose from.

I can do this, however, I don’t want the page to get ALL of the images and then randomly select one. I would like to just randomly select one, then load that image in order to keep requests and data to a minimum.

Here is what I have now:

<script>
    import heroOne from "$lib/hero.webp";
    import heroTwo from "$lib/heroTwo.webp";

    let heroImg;
    const rand = Math.floor(Math.random() * 2);
    switch(rand){
        case 0: heroImg = heroOne; break;
        case 1: heroImg = heroTwo; break;
    }
</script>

<img src={heroImg} alt="Some alt text">

As far as I know, this is still going to load both hero images. Is there some way to only load the image once selected?