He was a big man in the paint, and Shaquille O'Neal showed he also has a big heart to match, with his Facebook video paying tribute to first responders in wildfire-plagued Fort McMurray, Alta.

"Thank you to the incredible first responders in Fort McMurray. You guys are true heroes," the retired NBA star wrote in the caption for the video.

"Thank you from the bottom of my heart. You guys are the true heroes," O'Neal said.

"Love you guys. Love Canada. And thank you," he said.

He then belted out the last line of O Canada before signing off.

The video has more than one million views and has reached Facebook users who have been forced out of Fort McMurray.

"Shaq, on behalf of all the evacuees here in Fort McMurray, thank you so much!" wrote Elton Jarvis

"Thanks SHAQ! Classmate, LSU Class of 1993 here in Fort McMurray!" wrote Dennis Lee Banks, referring to O'Neal's college team at Louisiana State University.