The Thorn Fire: What Happened and What You Need to Know

Imagine a big outdoor fire (called a wildfire) that started near San Diego. Here’s the simple, friendly breakdown of what happened with the "Thorn Fire," based on reports from CalFire (the people who fight fires in California) up to Thursday evening.

What Is the Thorn Fire and Where Is It?

• The Thorn Fire is a brush fire (a fire in bushes and small trees) in southeast San Diego County near a town called Boulevard.
• It started on Wednesday afternoon around 3:30 p.m. near Buckthorn Trail in the Live Oak Springs neighborhood.
• A small structure fire (a fire in a building) in that area sparked the vegetation fire. Think of it like a house fire that jumped to the grass and bushes.
• The exact reason it started is still being investigated (like a mystery they are trying to solve).

How Big Is the Fire and Is It Under Control?

As of 6 p.m. Thursday (according to CalFire’s official page):

• The fire has burned 1,234 acres. An acre is about the size of a football field — so picture over a thousand of those on fire!
• It is 45% contained. This means barriers surround nearly half of the fire’s edges to keep it from spreading.
• The forward rate of spread has been stopped. In kid words: the fire is no longer getting bigger on its main active side. It’s not moving forward like a marching army.

Important Point: Stopping the forward spread does NOT mean the fire is out! There are still hot spots (little burning areas) inside the fire zone. Crews must keep working.

Smoke and Health Advice

• When the fire started, it sent huge plumes of smoke into the sky visible for miles.
• A smoke advisory (a warning to be careful with smoky air) was issued by the San Diego County Air Pollution Control District, but it was lifted by Thursday afternoon.
• Communities impacted: Live Oak Springs, Boulevard, Tierra Del Sol, and McCain Valley.

If you smell smoke in those areas:

• Limit outdoor activity (play inside instead!).
• Stay indoors if you can.
• Watch out for people with breathing or heart problems, older adults, and kids — they are more sensitive.

How Firefighters Fought the Fire

• Three night-flying helicopters (like flying water buckets) worked overnight into Thursday.
• They dropped water continuously on the active fire, which helped slow it down.
• CalFire said this gave ground firefighters "valuable opportunities" to build stronger containment lines.
• On Thursday, crews kept strengthening lines, putting out hot spots, and increasing containment.

Road Closures

• One lane of Interstate 8 (a big highway) between Crestwood Road and Ribbonwood Road was reopened in both directions.
• If driving there, check traffic conditions because closures can change based on fire activity or crew needs.

Evacuations: Leave or Get Ready

Evacuation means leaving your home to be safe. Here’s the color code:

• RED: Evacuation Order – Leave NOW to a safe place.

• YELLOW: Evacuation Warning – Danger might come. If you need extra time, have pets/livestock, leave now.

• Evacuation orders remain active for certain areas (see live map on Genesys).
• A Temporary Evacuation Point was at Golden Acorn Casino but closed Thursday evening.

Why the Fire Crossed the Highway

• Winds blew northeast, pushing the fire across Interstate 8.
• A threat to structures (buildings) remains in the burn area.

Tips: Preparing for a Wildfire Evacuation

CalFire recommends a "Go Bag" (a bag packed and ready if you must flee). Include:

• 3-day supply of non-perishable food & 3 gallons of water per person
• A map with at least 2 evacuation routes
• Necessary prescriptions or medications
• A change of clothes & extra eyeglasses/contact lenses
• Extra car keys, credit cards, cash, or traveler’s checks
• A first aid kit & sanitation supplies
• A flashlight & battery-powered radio with extra batteries
• Copies of important documents (birth certificates, passports, etc.)
• Pet food & water

Important Point: Always keep sturdy shoes and a flashlight near your bed for sudden night evacuations!

If you have time, add:

• Valuables that are easy to carry
• Family photos and irreplaceable items
• Personal computer data on hard drives/disks
• Chargers for cell phones/laptops

Firefighting Words Made Simple

CalFire Captain Robert Johnson explained tricky terms:

1. Contained – Fire is surrounded by barriers (fire lines, roads, lakes). "25% contained" = quarter of the edge is blocked, NOT 25% put out.
2. Forward rate of spread stopped – Fire not actively growing in size, but not contained/controlled.
3. Controlled – 100% contained, flames out, fuel cleared; crews still watch hot spots.
4. Out – No hot spots or smoke left at all.

Important Point: Even at 50% containment, you are NOT safe yet — hot spots can still burn inside.

What Makes Southern California Fire-Dangerous?

Dry, Warm Santa Ana Winds

• Desert air blows west to coast, gets compressed down mountains, warms up.
• Humidity drops, temps rise. These winds act like a fan to explode fire size.

Lack of Rain, Dry Vegetation

• Water year starts Oct 1; below-average rain = brown dry plants = fire fuel.
• More rain = lower fire risk.

Electrical Equipment Concerns

• In critical danger, power companies shut off electricity to avoid sparks.
• Heat + A/C use stresses grid; schools may close or become fire crew sites.

Summary

The Thorn Fire burned 1,234 acres near Boulevard, SD County, sparked by a structure fire Wed 3:30 p.m. As of Thu 6 p.m., 45% contained and forward spread stopped. Smoke advisory lifted. Helicopters helped overnight. Some evacuations active (RED/YELLOW), I-8 partially open. Pack a Go Bag, keep shoes/flashlight by bed. Winds pushed fire over I-8. Santa Ana winds, dry plants, and power gear add to fire risk. Stay informed via CalFire page.

FAQ

Q: What does "45% contained" mean in kid words?
A: Fighters built walls or used natural breaks around 45% of the fire’s edge. It does not mean 45% is extinguished.

Q: Is it safe to go outside if I live near Boulevard?
A: If you smell smoke, stay inside and limit outdoor play. Follow evacuation colors from officials.

Q: Why did the fire cross the highway?
A: Northeast winds acted like a push, moving the fire across Interstate 8.

Q: What should I pack in my Go Bag?
A: Food, water, meds, clothes, docs, pet stuff, flashlight, radio, and chargers if time.

Q: What’s the difference between "contained" and "out"?
A: Contained = surrounded but may burn inside. Out = no smoke or hot spots anywhere.