They say it was a propane tank in the SUV. No evidence of burning so this sounds like an intentionally bombing. There was a bomb threat in Boulder a day or two before this happened. Archive: https://archive.today/8X1h2 From the post: >>An SUV exploded near downtown Denver on Thursday night. The blast was heard in the area and people reported feeling it rattle buildings. The Denver Police Department said the call came in around 10:10 p.m. and police responded to the area near 6th Avenue and Speer Boulevard.