JUDY WOODRUFF: Although
crossings at the U.S.
southern border are
at historic lows, the

number of families and
unaccompanied minors entering
the U.S. has been increasing.

Amna Nawaz was granted access
to Border Patrol's Yuma
Sector operations in Arizona.

This is the first of
two reports, starting
with a view from the
U.S. side of the border.

And a warning: Viewers may
find some images disturbing.

AMNA NAWAZ: Under the hot
Arizona sun, with few belongings
and well-worn shoes, these

migrants have just crossed
onto American soil after
the nearly-4,000-mile
journey from Guatemala.

Some in the group allow
us to shoot video.

Florencio says he and his
4-year-old son, Walter,
traveled for 30 days.

He's desperate for work and
says there was none back home.

He and the others surrendered
to U.S. Border Patrol agents.

The agents didn't allow
us to record interviews
with the group.

But they invited us to spend
a day seeing what they do here
in the Yuma Sector in Southwest

Arizona.

The groups they're
encountering in recent years
have changed dramatically.

A decade ago, 90 percent
of immigrants caught
crossing illegally were
single adult men from

Mexico.

Today, nearly 90 percent are
families and unaccompanied
children from Central America.

That change, they say, is
stretching their resources
like never before.

At their headquarters,
Border Patrol shows us where
families are first detained.

Inside the headquarters is
what they call a processing
center, where families are held

for about three days.

And we're not allowed to
shoot any picture, but we
can tell you what we saw.

It's basically a
giant cement room.

And around the perimeter of the
room are a number of holding
cells that are broken up

by population.

So you have mothers and
daughters, fathers and sons.

But the single most crowded
room was for unaccompanied
males, just dozens and
dozens of teenagers

lying like sardines in
this one cement room.

What really strikes you
about the room, though,
is how many children there
are, toddlers running

around, infants in
their mother's arms.

The one thing border officials
will tell you is everyone can
agree this is no place for

families and children.

We could record video
in what they call their
Costco, a room once filled
with office supplies,

now packed with diapers,
formula, and family essentials,
unpacked here by some of the 90

National Guard troops
sent to backfill staffing.

ANTHONY PORVAZNIK, Yuma Sector
Border Patrol: This is what
we call an enforcement zone,

so this is triple-layer
fencing here.

AMNA NAWAZ: Yuma Sector
Chief Anthony Porvaznik says
he's asked for more agents.

He already has funding
from last year to update
25 miles of border fencing.

ANTHONY PORVAZNIK: This
will all be replaced.

AMNA NAWAZ: Into what?

ANTHONY PORVAZNIK: It will be
30 feet bollard-style fence.

AMNA NAWAZ: His resources,
he says, haven't changed
since 2012, but the job has.

Porvaznik estimates 35 percent
to 40 percent of his current
manpower goes to processing

and caring for the families
and children in custody.

ANTHONY PORVAZNIK: We just had
a lady last week who delivered
twins two months premature.

And they see -- they see
sick kids in our custody.

And last year alone, we took
550 kids to the hospital here,
over 1,700 total here just

in the Yuma area.

That's a huge strain on
our resources, because
they're doing things that
are not enforcement-related.

AMNA NAWAZ: But agents
concede no barrier is
100 percent effective.

They point us towards
the surveillance
videos showing families
climbing over sections of

wall.

The 14-year-old girl
in this clip broke her
vertebrae from the fall.

Injuries, they say,
are common and further
stretch their resources.

How far back does this date?

ANTHONY PORVAZNIK: This
dates back to about 1990.

AMNA NAWAZ: Chief Porvaznik
believes updating older wall
will dissuade people from trying

to cross illegally.

When you see people who are
willing to dig under this and
climb over barbed wire and

build makeshift ladders to climb
over additional fencing, do
you think that that's enough to

deter people to try to
breach it in some way?

ANTHONY PORVAZNIK: The majority
of the population, yes.

AMNA NAWAZ: Yes?

ANTHONY PORVAZNIK: It
will deter the majority.

And what we're trying
to do is impede and deny
entry into this area.

And so, 87 percent of the people
that we apprehend right now are
family units and unaccompanied

children.

They won't go over
a 30-foot bollard.

Is it going to push
it somewhere else?

Likely, yes.

AMNA NAWAZ: Later in the day,
Border Patrol encountered a
second group of Guatemalans

migrants.

This mother of two
young children asked we
don't show their faces.

She's fleeing her
abusive husband.

She and the rest of this
group of 12 waited across the
Colorado River to get into the

U.S.

CARL LANDRUM, Yuma Sector Border
Patrol: These are things that
we have to interact with here

on the ground.

AMNA NAWAZ: Deputy Chief Carl
Landrum walked us through the
brush to show us where they

crossed.

The fact that people are
willing to make a crossing like
this with little kids tells

you what people are willing
to do to come to the States.

CARL LANDRUM: It definitely --
it definitely shows that people
want to experience the American

dream.

And we would like for everybody
that could be a part of
that legally to be a part of

it.

AMNA NAWAZ: But immigration
attorney Laura Belous of the
Arizona-based Florence Project

says resources should go
to immigration courts,
not physical barriers.

LAURA BELOUS, Attorney,
Florence Project: If you look
at the history the border over

the last 20 years, increased
walls within cities then
pushed people into deserts.

So, if there's walls
and deserts, it is going
to push people into
canyons and rivers, where

people are likely to have
even more dangerous crossing.

Smuggling will be
even more expensive.

That then makes everyone
along the border less safe.

AMNA NAWAZ: Chief
Porvaznik says, whatever
the solution, the current
situation is unsustainable.

ANTHONY PORVAZNIK: Look,
we can't arrest our
way out of the problem.

That's not going to
solve the problem.

So we have to figure
out -- and this is not
a Border Patrol solve.

This is -- this comes from
legislation, updated laws.

AMNA NAWAZ: As the policy debate
in Washington drags on, there's
little relief in sight for

both those patrolling
this border and those
seeking to cross it.

Officials say the vast majority
of those crossing are families
seeking stability or safety,

though they also say background
checks sometimes reveal someone
with a criminal history.

Judy, it's worth noting that
criminal history often means
an immigration violation, not

necessarily a violent crime.

But Border Patrol officials'
bigger concern is who they're
missing while they're busy

caring for these
families and children.

So they say they want
everyone to cross legally.

And that will be the focus of
our piece tomorrow evening.

JUDY WOODRUFF: And we're very
much looking forward to that.

Thank you.

AMNA NAWAZ: Thanks, Judy.