A woman and her horse were killed after they were struck by lightning in Sedalia on Sunday afternoon.

According to South Metro Fire Rescue, it happened a few hundred yards behind a home on the 7000 block of Rainbow Creek Road on a riding path. 

The Douglas County Sheriff's Office tells 9NEWS a 37-year-old woman was killed around 3:30 p.m. Her name has not been released.

Radar shows there was one strike near Sedalia, and three strikes near Roxborough on Sunday afternoon. 

A 15-year-old girl was also seriously injured and taken to the hospital. South Metro says this girl, a family friend, was also riding a horse. A third rider, who turned out to be the mother of the 37-year-old, was far enough away at the time and uninjured.

The three saw the storms, and were looking for a place to meet up. 

Lightning is the number one weather-related killer in Colorado.

Details at this time are extremely limited. 9NEWS will update this story as more information is released.