Police believe he had been there for 20 hours and nobody called for help.
Detectives said witnesses told them that some people even stopped to snap cell phone pictures of the homeless man's half naked body.
"If they just had used their cell phone to make a call instead of a picture, perhaps this man could still be alive today," said Sgt. Brian Harris of the Houston Police Department. "I would like to say our city is better than that, I know our city is better than that."
Alice Davis works at a business down the street, and she knew the man simply as "Big Guy".
"He would come in and say can I get a quarter, can I have a cup of coffee, sometimes he would ask to use the bathroom," Davis said. "I'm thinking the man was asleep, so nobody knew he was really dead."
Police believe the man died of natural causes. The medical examiner will determine his identity and notify his family.