When the world's oldest roller coaster breaks at the worst possible moment, skilled engineers and technicians race against the clock to investigate what went wrong and how to fix it before it's opened to the public.

Working thousands of feet above the California desert, brave engineers and fearless crews perform perilous high-wire acts to keep the a hi-tech tramway system operating safely for the hundreds of daily tourists it transports.

Brave lighting technicians battle extreme desert conditions to keep the lights bright in Las Vegas; they put their lives at stake to perform risky neon bulb replacements at terrifying heights and surrounded by hundreds of volts of electricity.

When sea levels rise, storm surge barriers work overtime to fight off devastating floods; to get this tough job done, a team of experts maintain these engineering marvels to prevent catastrophe and keep millions of people safe.

Maintenance crews at a remote airstrip are exposed to the elements as they keep water-bombing aircraft flying to battle forest fires, and mechanics race against the clock to get transport helicopters to safely shuttle oil rig workers.

Fearless technicians battle staggering heights and fierce winds to upgrade a communications tower that keeps millions connected; special access to this dangerous job site reveals what it takes to get the job done.