The wreck happened early Monday near Schertz, about 15 miles northeast of San Antonio.
Schertz city spokesman Brad Bailey says a woman was southbound in the northbound lanes of I-35 when her car hit an SUV.
Bailey says a tanker truck went around the original accident site and hit two people who stopped to help, plus the wrong-way driver. The wrong-way driver and the two good Samaritans, including a tour bus driver and a nearby rest stop worker, were killed.
Bailey says five people in the SUV suffered minor injuries.
Investigators are trying to determine if alcohol played a role in the accident.
Names of the victims weren't immediately released.
