Without warning, the brake pedal on my 2019 Chevy Blazer became hard, almost as if the car was turned off. I was unable to stop and slowly rolled into the back of a semi stopped at a stoplight. This was moments after exiting off of a major highway and could have been much worse. The car was taken to a mechanic and it was determined to be a failure with the brake booster. GM has issued recalls for this problem in several other models but the Blazer has been excluded. Based on online forums and complaints of multiple other Blazer owners, it seems obvious that Blazers should have been included in the recall.