"The driver had an acute stroke while on the wheel and lost control of herself," said acting Bangkok police chief Pol Lt Gen Sanit Mahataworn said on Saturday.
"Her daughter, who was with her in the car, told us her mother suddenly had a seizure and lost control of the car before it hit the shrine," he said.
"The closed-circuit camera footage showed the car was in reverse gear after the hit. But that's because the daughter was pulling the gear lever or the impact could have been much greater," the police general explained.
"This was not a terrorist or deliberate act to hurt anyone. It's an accident," he added.