So among the Pacific surf liner writing writing from San Juan Capistrano to San Diego today.

That's our colleague Jim Carleton, riding one of California's busiest train lines, the surf liner.

We're going maybe 50 miles an hour

zooming past traffic on the nearby five freeway and it's really beautiful.

We've been passing gorgeous beaches.

You can see surfers, you know, crashing waves. I was looking for dolphins,

I couldn't find any of dolphins, but I was looking. The train runs for 351 miles, all the way from San Diego to the

Central Coast of California. They make stops in Orange County, Los Angeles, and

Santa Barbara.

It's called the surf liner because it runs alongside the ocean,

and in many places on top of cliffs.

When you look closer, the bluffs above the track in many places are crumbling. You can see

tarfs of plastic, you know keeping the erosion at bay on the beach side you can see giant boulders in many

stretches separating the tracks from the waves crashing just maybe 20 or 30 yards away.

So it's pretty clear there's a real fight against mother nature here.

Erosion, crashing waves, crumbling bluffs.

The surf liner is basically at risk of falling into the ocean.

The first 130 years that this line was in existence,

the track through St Clementi, for example,

had to close only three times.

The last three years has happened five times.

Wow. Five times there have been, you know, the bluffs have been destabilized enough to close the

...