Thomas Phelan, who was hailed a hero after rescuing hundreds of people during the Sept. 11 terrorist attacks, has died of cancer.

Phelan, 45, who died Friday, is highly recognized for his efforts on the harrowing day as he turned his ferry into a rescue boat. He is one of the thousands of cancer victims linked to 9/11.

Phelan worked for Circle Line Statue of Liberty ferry cruises when the Twin Towers were hit and helped ferry people from Lower Manhattan, FDNY spokesman Jim Long told CNN.

He went on to become an FDNY firefighter in 2003 and was later promoted to marine patrol.

Following the attacks, droves of people have been diagnosed with cancer as a result of exposure to carcinogens and pollutants.

Doctors with the World Trade Center Health Program have been able to link 70 different types of cancer to Ground Zero, Newsweek reported in 2016.

It is unclear what type of cancer Phelan suffered from.

In the aftermath of Phelan’s death, numerous people have taken to social media to remember his selfless heroism.

"In our city's darkest hour, @FDNY firefighter Thomas Phelan's heroism saved hundreds of lives," Mayor Bill de Blasio said on Twitter. "We will never forget his service and his sacrifice."