Story highlights Carmelo Mercado retired from the fire department after September 11, 2001, terrorist attacks

A doctor said he had suffered too much lung damage

In May, he bought a winning $5 million lottery ticket

New York (CNN) New York City firefighter Carmelo Mercado retired after suffering lung ailments from his time working at ground zero after the September 11, 2001, terrorist attacks.

A former member of Battalion 49 in Astoria, Queens, Mercado, 63, on Thursday received the $5 million top prize from a Cash X100 scratch-off lottery ticket.

"I'm now a part of the New York lottery family," Mercado said at news conference.

Mercado's career ended after 9/11 because of health problems that continue to affect him, he said. He now devotes his time to being a father to his four children, including a 10-year-old daughter.

He retired in 2004 after a doctor at the fire department told him he had too much lung damage to continue to work.

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