I think the last non negligible accident including vinyl chloride was 2012, and it was ~6x less bulk volume than this one (20k gallons as opposed to 120k)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5776704/
And it wasn't managed via a controlled burn.
Buttegieg should know that it's not about the number of derailments but the chemicals involved, the volume / mass involved, the conditions of leakage / spillage, environmental spread and finally the chosen response to mmmanage (which sometimes can make the problem worse or trade one problem for another)