Joseph Cassano worked as a fire department emergency medical technician.
Commissioner Salvatore J. Cassano calls the situation "very painful." He said Monday he loves his son and believes his resignation was the right decision. The commissioner says the department has worked hard to achieve diversity, inclusiveness and a good reputation.
Mayor Michael Bloomberg said he was among those who found the messages offensive.
The younger Cassano said he regretted the posts and had treated every patient with great care and respect.
The New York Post ( http://bit.ly/1133wJg) said the statements included a derogatory term to describe blacks, and a tweet stating he liked Jews about as much as Hitler did.