Red Lightning bolt and engine knock

I had my oil changed before traveling from North Carolina to Florida. Car made it to Florida without issues. The next day I was driving and the red lightning bolt appeared on dash and car died soon as I pulled over. Let car sit for a few minutes trying to read up on the issue in manual and attempted to crank car. Upon cranking car it began making a hard knocking sound and would not turn over. I also smelt exhaust fumes in the cabin, so I replaced the EGR valve thinking that would fix it but it did not. What could be the problem?