NEW YORK (CBSNewYork) — The Metro-North Train engineer who was driving during a deadly derailment in the Bronx in December 2013 has retired with a pension.

As WCBS 880’s Peter Haskell reported, William Rockefeller has not worked since the derailment near the Spuyten Duyvil station. But he is now receiving a disability pension.

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“There was an independent objected determination made by an independent tribunal that he’s not capable of returning to work as a train engineer,” said Rockefeller’s attorney, Danny Seymour.

Seymour would not comment on the nature of the disability. However, Rockefeller was found to have undiagnosed sleep apnea.

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Seymour said Rockefeller is still haunted by the incident.

“His thoughts are with the all of the passengers on that train,” Seymour said.

The derailment took place near the Spuyten Duyvil station in the Bronx on Dec. 1, 2013. Four people — James Lovell, Donna Smith, James Ferrari and Kisook Ahn — were killed, and more than 70 were injured.

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In October 2014, the National Transportation Safety Board concluded that a sleep-deprived Rockefeller nodded off at the controls of the train just before taking a 30 mph curve at 82 mph.