The failure of this unpermitted hillside retaining wall was triggered by the collapse of a tree in this location, which undermined the surrounding area. The remnants of the roots provide clear evidence of the tree's considerable size and its impact on the landscape.

Although the retaining wall was unpermitted and clearly not built to last, this picture shows us how plants and trees help stabilize hillsides by anchoring soil with their root systems, absorbing water to prevent saturation.

Not a single post in sight.

Post and piers are essential structural elements in a building's foundation, providing support to a structure and distributing the weight evenly to the ground below.

You can really see how steep this hillside is in this photo. It is important to properly mitigate hillsides as they are prone to landslides and can cause significant risks to people and properties, as seen in the photos above.

Following the landslide, the hillside was tarped up for stabilization. This tarping was not done by us.

The failure of this retaining wall is likely due to inadequate footing embedments. It is leaning by over 12 inches and is nearly touching the adjacent building.

Tag you’re it.

This substantial crack in the crawlspace was wide enough to fit this entire clipboard.

This huge crack was caused by clay soil. This type of soil can lead to significant cracking due to its tendency to expand when wet and contract when dry, causing substantial movement to occur.

Typically, a slab foundation rests directly on the earth with footings around the perimeter for support. Meanwhile, a post and pier foundation consists of concrete piers and wooden posts that provide support for the joists and girders.

This specific situation is uncommon as these are different types of foundations and can function effectively on their own if done properly.

This homeowner was having issues with water intrusion.

Water intrusion can cause significant damage as well as pose risks to both the structural integrity of the building and the health of its occupants.

It must have been “Bring Your Own Post and Pier to Work Day” that day.

The interior stem wall exhibits a crack approximately half an inch wide, accompanied by a rotation of 5/8 to 3/4 of an inch, indicating significant structural movement.

Thank you for joining us, we hope you enjoyed, we'll see you next Tuesday at 2 pm!

For over 30 years now, Alpha Structural, Inc. has developed a powerful reputation as the #1 Foundation Repair, Landslide Repair and Earthquake Retrofitting Contractor in Los Angeles and Orange County.

The steep vertical slope of the wall adds to the safety concerns, even more so now that it's failing, potentially leading to issues for the homes that are downslope.

The impact of the landslide has resulted in significant damage to all the homes in the area. This is the neighboring home. There are big cracks, huge separations in the structure, slanted windows, and more, all indicating extensive soil movement from the landslide.

Mud bath anyone?

We often get called out to assess homes in the area and are met with the most disastrous structural damage.

When you really put it into perspective, the force needed to break apart these thick concrete pavers is extreme.

The recent heavy rains triggered a massive landslide on this extremely steep hillside, causing significant damage to this home.

Different assessment, more spall damage.

Spalling is commonly caused by the corrosion of embedded steel reinforcement bars or steel sections, which weakens the concrete and leads to it breaking apart.

Retaining walls are designed to retain soil, but when heavy rainfall adds extreme amounts of water weight to the equation, it can exert significant stress on the wall.

This gunite wall, meant as a remedial repair to mitigate debris, has aged and begun to fail.

This huge crack is a result of an exorbitant amount of stress pulling the house apart due to land movement in the area.

The severe spall damage in this building has been accumulating and progressively worsening over the past few years, posing significant structural concerns.

The framing of this detached garage is completely rotted, and the foundation supports are rotating out of square, possibly due to inadequately embedded footings on a steep slope.

This sagging beam was crushed due to water seepage that resulted in wood rot, leaving the beam to no longer provide the proper support needed for the structure.

Poor drainage from the street above led to slope failure in this area. Additionally, the deck and block wall were constructed without proper permits and lacked the footings capable of withstanding the elements.

The caisson is now exposed and is beginning to be undermined as well, emphasizing the structural issues of the building.

A landslide caused this foundation to completely fail and become unattached from the home. Currently, the foundation is sitting under the plastic tarping.

Hairline cracks are generally considered normal wear and tear. However, cracks measuring a quarter of an inch or larger, such as this one, can indicate structural issues.

Basically, a finger should not be able to fit inside a crack.

The significant cracks and openings in this home suggest possible differential settlement.

Some debris that was left behind from a landslide. Implementing effective slope stabilization measures is recommended to minimize the impact of natural disasters and prevent potential damage.

Due to a landslide, this home is now severely undermined. The landslide spanned across three properties, causing extensive damage and posing safety risks to the affected area.

Differential settlement is where one part of the foundation settles more than another due to soil conditions or other factors.

The scale of this landslide was immense, affecting two commercial buildings.

SoCal showed us a great example of, "When it rains, it pours."

Getting proper support, such as an engineered retaining wall, can help prevent incidents like these. Retaining walls are engineered and built to support and hold back hills, which provides structural stability and reduces the risk of mudslides and soil runoff.

Due to the rains, landslides have been occurring all across Southern California, posing significant challenges for homeowners.

The force of this landslide was strong, bringing down a railroad-tie wall and leaving the backyard unsupported, giving it a cantilevered look.

This retaining wall originally sat at the top of the hill. The heavy rains triggered a landslide and sent it tumbling downhill.

Thankfully, the house didn’t follow.

An outside view of the home vividly showcases the magnitude of the landslide's impact as it found its way into the residence, leaving a trail of destruction.