18-Wheeler Crash and Hazmat Spill Shut Down Busy San Antonio Ramp for Hours

A morning commute in San Antonio turned into a major traffic mess after an 18-wheeler overturned near downtown and triggered a hazardous materials response.

The crash happened early Thursday, June 4, near the Finesilver Curve, a busy highway connection where I-35 South meets I-10 West. According to MySA, the crash happened around 4:38 a.m. and shut down the connector ramp from I-35 South’s upper level to the I-10 lower level at US-87.

That is one of those spots in San Antonio where a crash can cause problems fast.

The ramp is not just a random stretch of road. It is a key connector for drivers moving through downtown, heading toward the West Side, or trying to link between major interstates. When an 18-wheeler overturns there, traffic does not just slow down. It backs up, reroutes, and spills into surrounding roads.

According to the San Antonio Express-News, the crash shut down the southbound I-35 to I-10 West exit at the Finesilver Curve for about 10 hours. The outlet reported that the ramp reopened around 1 p.m. after the early morning wreck.

Police said the truck driver, a 64-year-old man, was traveling too fast and lost control. The preliminary report said the 18-wheeler veered out of its lane and struck another vehicle driven by a 31-year-old woman before the rig overturned.

Both drivers reportedly suffered minor, non-life-threatening injuries.

That part is fortunate, because a crash involving a big rig on a curved interstate ramp can easily become far worse. An overturned 18-wheeler creates immediate danger for the driver, nearby motorists, emergency crews, and anyone stuck behind the wreck with nowhere to go.

The hazmat response added another layer to the situation.

The Express-News reported that an oil spill from the wreck brought in a hazmat crew. That kind of cleanup can take hours because crews have to contain the spill, keep it from spreading, protect drainage areas, and make sure the roadway is safe before traffic can resume.

For drivers, that means the crash does not end when the vehicles stop moving. Even after the people involved are checked out and the wreck is secured, the cleanup can keep a highway ramp closed through the morning.

TxDOT warned drivers to avoid the area and use alternate routes. MySA reported that motorists were advised to detour by exiting at San Pedro and using Culebra Road to reenter westbound I-10.

Anyone who has driven that part of San Antonio knows how quickly one closure can create a headache. Downtown ramps already require attention, lane changes, and patience. Add a big rig rollover, emergency vehicles, and a hazmat cleanup, and the whole morning commute changes.

The location also has a reputation.

The Express-News noted that the Finesilver Curve has seen other 18-wheeler rollover problems, including another crash earlier this year involving a truck carrying bees. The curve is known for being difficult for large trucks because of its design and the sharp speed reduction drivers face going through it.

That makes Thursday’s wreck more than a one-off traffic story.

It raises the same questions San Antonio drivers have asked before: why do big trucks keep overturning there, are warnings enough, and what can be done to keep a dangerous curve from repeatedly turning into a shutdown zone?

For now, police have pointed to excessive speed as a factor in the crash. But for commuters who spent the morning stuck in traffic, the bigger issue was simpler.

One overturned 18-wheeler brought a major downtown connector to a standstill for hours, and it happened on a stretch of highway that many drivers already treat with caution.