WESTMINSTER, Texas -- Tragedy has rocked a small town in Collin County following the deaths of four people killed in a Tuesday crash on State Highway 121.

On Tuesday, Chief Sam Geer was the first to respond to "the worst accident I've seen here," he said. He's referring to a five-vehicle accident that left four people dead and nine seriously injured. It happened on Highway 121 near County Road 528, just outside of Anna.

Sam Geer is one of the nine volunteer first-responders who did not sleep well last night. Geer says when he arrived on scene, he could see a body laying in the middle of the road.

"I should be a little more composed than this, but I'm just thinking about them and their families," said Geer.

Abigail Kendall, 15, Brianna Gesino, 15, Julie Trimble, 51, and Wayne Trimble, 51, died at the scene, DPS said.

Kendall and Gesino were students at Anna High School. A student, Kodie Pitre, knew Abigail just from brief conversations she had with her in between classes. She describes her as a "sweet person."

"It just makes you think that one day we can be here and the next day, we're never promised tomorrow," Pitre said.

Heather Trimble, who was eight months pregnant, and her 4-year-old daughter Matilda were seriously injured traveling with their family, Wayne and Julie. Heather gave birth right after the crash.

The investigation into what happened continues. It is a tragedy that can humble even the most hardened and strongest people like Geer.

"I thought I'd seen everything in the Navy. I did three tours in Vietnam, but evidently, I didn't see everything," he said.