According to a News 4 San Antonio report, the driver was transporting fifth and sixth grade students from Schertz-Cibolo-Universal City ISD's Schlather Intermediate School on Monday afternoon.
Fifth-grader Serenity Hugo told the news station that the driver began "shaking" and that "stuff was coming out of his mouth."
Photos from the scene show the bus on the lawn of a home on Landmark Haven. According to reports, the driver fell unconscious, causing the bus to hop the curb and clip a tree. The vehicle only stopped after Hugo pushed a button, which she said the driver had advised students to do if he ever suffered a seizure.
No one was injured, although KSAT reports that multiple students said they were "traumatized" by the incident.
Ed Suarez, spokesman for the district, told News 4 that the driver completed a medical exam in September, and that the district was unaware of any medical condition.
Investigators are now reviewing surveillance video from the bus.
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