(dramatic music) - California is a state that has been prone to wildfires for as long as the land has been there.

That has become more true as the climate has changed and we've seen longer droughts, more intense heat waves, and that has made it so that the risk of a very deadly and destructive fire has become heightened, and all of the state's utilities have had power lines that have ignited large-scale fires over the last 10 years.

But some of the most deadly and destructive have been started when PG&E's power lines have failed.

(tranquil music) PG&E has had a number of challenges over the last two decades.

There was an energy crisis in California in the early 2000s that ultimately pushed it to seek bankruptcy protection.

The few years in which it's emerged from bankruptcy, they were focused on delivering returns to shareholders.

The company was also focused on procuring wind and solar contracts, basically at the behest of the state.

Wind and solar power were much more expensive than they are today, so the company faced additional pressure to keep expenses low.

(tranquil music continues) The company is still tasked with maintaining the infrastructure.

It's a sprawling service territory.

It covers 70,000 square miles.

Part of it involves managing trees that have the potential to touch live wires, looking at the strength of the structures, the integrity of the hardware.

In November 2018, the hook on a transmission tower that was 100 years old broke and dropped a live wire that showered the ground with sparks.

(sirens blaring) The component that broke had never been replaced.

The company had known of the risks, and yet done very little to mitigate them.

(dramatic music) It destroyed the town of Paradise, and several nearby towns in the Sierra Foothills north of Sacramento.

Eighty-four people died.

(dramatic music continues) - If you look at the three disasters in California, Texas with the freeze, and in Puerto Rico with the hurricane, they seem so different, but they're all part of a broader trend of intensifying weather extremes.

(dramatic music continues) - After Hurricane Maria, around 200,000 people left, some came back, many didn't.

I don't think that's something that can be measured in any other way than how important is the access to a reliable energy supply?

(dramatic music continues) - [Announcer] This is "Power Trip.

The Story of Energy."

(dramatic music continues)