An elderly woman and her 9-month-old grandson were killed and her daughter injured when their motorcycle was hit from behind by a pickup in Phra Pradaeng district early Sunday night, police said.
They accident occurred in Soi Suksawat 78 in tambon Bang Chak.
Chatchada Kaewkham, 35, told police that she was returning home on her motorcycle with her mother, Sawoey Srasi, 60, and her 9-month-old son riding pillion.
Ms Chatchada said she felt the impact as her motorcycle was hit from behind.
All three of them were thrown off the bike and onto the road. She was knocked out. When she regained consciousness she found her mother and son dead on the road with multiple injuries.
The driver of the pickup that hit them waited for police to arrive. He was taken to Phra Pradaeng police station. A breath test found he had been drinking alcohol.
The driver was charged with reckless driving and driving under the influence, causing death and injury. His name was not known.