AUSTIN (KXAN) — The Bexar County Sheriff's Office said that a 20-year-old teacher died and several children were injured in an accident Thursday afternoon at a school on West I-10 Frontage Road in Boerne, Texas. Emergency responders transported the driver and five children to nearby hospitals as a "precaution" following the accident, according to Bexar County Sheriff Javier Salazar. At the time of the accident, parents were picking up students from a school holiday party. "This is a heartbreaking scene," he said. "A parent had loaded her children into her vehicle, then, for whatever reason, accelerated into another vehicle. That pushed the other vehicle into a fence." Salazar said his investigators don't believe the crash was an intentional criminal act or caused by intoxication. "[The driver] does have a past medical history that may have contributed to this," he said. "It may have been a medical issue that took place." Next of kin for the adult and the children have been notified. The identities of those involved wasn't released by the sheriff.