A Houston police officer who rescued more than 1,500 people from historic flooding during Hurricane Harvey last year while battling stage-four colon cancer has passed away.

Norbert Ramon left his cancer treatment last August when Hurricane Harvey made landfall on the Texas coast and hovered over Houston, submerging neighborhoods across the city.

He and other officers used four police boats to move the scores of stranded Houstonians out of flash flooding in northern and eastern parts of the city over a three-day span.

“My main concern was to help the citizens,” Ramon told WFAA then. “Nothing else was on my mind. I didn’t worry about me or anything.”

Ramon’s battle with cancer ended Friday, Houston police confirmed.

“Today our [Houston police] family lost a great colleague, husband, father, friend, cop, hero, with the passing of Senior Police Officer Norberto Ramon,” HPD chief Art Acevedo wrote on Twitter. “He served honorably for nearly 25 years. Despite being seriously ill, he showed courage & grit as he saved dozens of lives during [Harvey].”

In January, the Houston Texans surprised Ramon with Super Bowl tickets – the big game was played at Houston’s NRG Stadium – as a thank you for his heroism months earlier.