Component/s: Storytelling Tool UI
Add feature detection (using a library like Modernizr or equivalent) or make use of progressive enhancement/graceful degradation strategies in order to get the site functioning to a bare minimum standard on older devices. Browser detection specifically is not recommended, but would be an adequate short-term solution.
In particular, the Speech Synthesis API (which only has partial support in older browsers)
An example of the current setup failing would be IE11 not supporting Speech Synthesis, and so the storyViewer component fails to load, so the site is effectively useless. This could be solved by disabling and/or not loading the Orator for browsers that don't support it.
This approach may also be useful with respect to the usage of CSS Grid or other features in HTML, CSS and JS which are not supported very far back.