Multiple crashes involving semi-trucks slow traffic across San Diego County

SAN DIEGO (FOX 5/KUSI) -- Drivers in various parts of San Diego County encountered stop-and-go traffic Thursday afternoon due to multiple crashes, including a deadly crash and a couple of which involved semi-trucks.

The crashes were reported amid rare August rainfall ranging from light to heavy hitting some parts of San Diego County due to remnants of what was Tropical Storm Juliette.

The SigAlert map below shows which San Diego County roadways were impacted by traffic slowdowns as of 3:15 p.m.

An incident shortly before 1:30 p.m. on northbound Interstate 15 near Interstate 8 involved a semi-truck that had jackknifed against a concrete wall, per California Highway Patrol logs. The crash led to at least one northbound lane of I-15 being blocked off to traffic.

Traffic was reportedly backed up all the way to El Cajon Boulevard from Camino Del Rio/I-8 due to the crash, per SigAlert.

Then, another crash involving a semi-truck occurred near National City around 2:45 p.m.

According to CHP, an Amazon delivery semi-truck had collided with a tree. The truck and trailer were seen hanging off the off-ramp of northbound Interstate 805 near eastbound State Route 54.

Images below captured by FOX 5/KUSI at the scene showed the extent of the damage.

National City Fire Department Battalion Chief James Stiles told FOX 5/KUSI that the truck had potentially hydroplaned off the roadway and down an embankment.

"Fortunately, it wasn't really a rescue. The driver we were able to get out without any difficulty, but the driver was transported to UCSD as a 'major trauma,'" Stiles said.

Around 3:49 p.m., another crash occurred in Ramona along Highway 78 and Weekend Villa Road, according to Cal Fire San Diego.

Authorities say a vehicle crashed 30 feet off the roadway, killing one man and injuring another who was taken to the hospital. No other vehicles were involved.

Both directions of State Route 78 have been closed from Weekend Villa Road to Haverford Road for an unknown duration of time due to the accident, per CHP logs.

In La Mesa, SkyFOX/KUSI in the Sky was over a rollover crash around 5:15 p.m., on Interstate 8 westbound and El Cajon Boulevard. Multiple vehicles were involved in the collision with one flipped onto its roof. First responders appeared to be providing aid to some of the victims.

Stiles reminded drivers to be extra cautious on the roadways during rain events.

"This is the perfect example of where it happens, these turning on-ramps, off-ramps," he said. "Slow down before you get to the on-ramp, not hit the brakes as you're sliding -- that's already too late."