This kind of thing makes me crazy. I'm in the D/FW Texas area and took my son to a premier children's hospital in Fort Worth, Cook Children's, when he was having stomach pain. When we went into the ER I was shocked, it was standing room only Mexicans and it was a LARGE waiting room. I thought we had stepped into Mexico. Luckily, I had taken my son to the pediatrician first so we got right in. An hour later my son was having emergency surgery for appendicitis. If I had of taken him to the ER first we would have had to wait for hours. This was months ago and I'm still mad about it.
I have read that Mexican ambulances will take Mexican nationals and drop them off in border hospitals in the U.S. not because they are closer mind you, but because they patients, victims, don't have to pay.