Michael Gansas, who failed to comply with a subpoena from the National Transportation Safety Board for a second day, was under medical supervision and was unable to talk about the accident, his attorney said.

"I am extremely disappointed that for the second time this week the captain has not been made available to speak to our investigators," NTSB Chairman Ellen Engleman said in a statement.

Gansas failed to appear for an interview on Tuesday and the safety board took the unusual step of subpoenaing him for questioning on Wednesday. A third date has not been set.

The captain's refusal to talk, after the crash on Oct. 15 that killed 10 people and injured or maimed dozens of others, raised the ire of the mayor.

"A person like that has no business working for the city, and we will take every legal action we can to get his testimony," Bloomberg told a news conference.

The city's Department of Transportation said it was initiating steps to fire Gansas, who was supposed to be in charge of the boat that crashed into the Staten Island terminal at the end of the trip from Manhattan.

Investigators want to question Gansas about his oversight of assistant captain Richard Smith, who was at the controls of the 310-foot (94 meter) vessel when it plowed into a pier. The ferry was carrying 1,500 passengers.

Reports have said Smith may have become temporarily incapacitated before the accident.

Smith remained hospitalized in critical condition and also has not been interviewed by investigators. After the crash, he fled the scene and attempted suicide.

No criminal charges have been filed but a spokesman for the Staten Island District Attorney said an investigation was underway.

Gansas' attorney Stephen Sheinbaum said his client had been advised to avoid further stress "in the immediate future."

"Mr. Gansas plans on cooperating fully with the investigation when he is legally and medically free to do so," he said, adding that Gansas was being "unfairly vilified."