A Mexican firefighter who volunteered at Ground Zero for three months and was later diagnosed with a respiratory condition linked to toxic fumes died Sunday.

Rafael Hernandez, 49, was found in his Queens home.

The medical examiner will determine the cause of death.

After moving to New York, he worked at an electronics shop near the World Trade Center.

When the planes struck, he rushed to help.

Later he became an advocate for other Hispanics who sickened after working at the site.

“We have lost a leader,” Rosa Duque, a Guatemalan immigrant who suffers from respiratory and stomach problems, said at his wake in Corona.

Hernandez had led a biweekly support group called Frontiers of Hope where the workers discussed their illnesses.

At his wake, friends paid tribute.