Delta IV Heavy rocket delayed again, raising concerns of aging infrastructure

This seemed comparatively unspectacular at first. But I'm not savvy enough to make out terms such as ‘RSLS abort’ in the dialogue (let alone knowing what they mean); luckily I quickly found a noob-friendly write-up that filled me in: https://en.wikipedia.org/wiki/STS-41-D#Launch_attempts

> While evacuating the shuttle, the crew was doused with water from the pad deluge system, which was activated due to a hydrogen fire on the launch pad caused by the free hydrogen (fuel) that had collected around the engine nozzles following the shutdown and engine anomaly. Because the fire was invisible to humans, had the astronauts used the normal emergency escape procedure across the service arm to the slidewire escape baskets, they would have run into the fire.

Whoa ◎﹏⊙. Not quite what I'd call ‘neat’.