Hm. Page loads fine for me in Firefox. Has for years (unlike google maps itself where oddly I get blocked for their 3d mode, even when that same mode works fine on earth.google.com)
If you're on Linux, maybe check your drivers, or do webgl.force-enabled layers.acceleration.force-enabled ?
If you're on Linux, maybe check your drivers, or do webgl.force-enabled layers.acceleration.force-enabled ?