In the last 10 days, in St. Landry Parish, Louisiana, three historic, predominantly black churches have been burned down.

This weekend, the 145-year-old Mount Pleasant Baptist Church was burned down. St. Mary’s Baptist Church, just a few miles away, burned down on March 26. Greater Union Baptist Church burned down a week later. They too, were more than 100 years old.

Investigators are currently working to find out the cause, with Louisiana State Fire Marshal Butch Browning telling NBC News, “Right now, what we have to say is that the fires are suspicious. We do believe that crimes have occurred. We believe that the three fires obviously are not coincidental, they are related.”

In a reference to acts of violence and the burning of churches in the civil rights era, Browning added, “We know the past and we know the history and it certainly drives our investigation. I think it brings more passion to our investigation to quickly get answers.”