DENVER (CBS4) – A 25-year-old bull rider is dead after an event at the National Western Stock Show Tuesday night. He was identified as Mason Lowe by Professional Bull Riders CEO Sean Gleason in a tweet.

We are deeply saddened to report that Mason Lowe passed away this evening following injuries sustained at the PBR event in Denver. The entire PBR and National Western sports family extends our heartfelt condolences and deepest sympathies to Mason’s wife Abbey and his family. pic.twitter.com/nFtVoIWj0K — Sean Gleason (@pbrceo) January 16, 2019

Gleason said ” We are deeply saddened to report that Mason Lowe passed away this evening following injuries sustained at the PBR event in Denver. The entire PBR and National Western sports family extends our heartfelt condolences and deepest sympathies to Mason’s wife Abbey and his family.”

A witness who was at the bull riding event told CBS4 Lowe was bucked off and then the bull stepped on his chest. Apparently Lowe got up, took a few steps and then collapsed.

Another witness, Aurora resident Gerardo Alvarez, told CBS4 “He was thrown off the bull and while he was on the ground the back legs stomped him in the chest while he trying to get up. When he got up he immediately grabbed his chest and stumbled over to the exit and then fell to the ground again grabbing his chest before he could get out of the area. They took him out on a stretcher.”

Lowe was from Exeter, Missouri, and was one of the top ranked bull riders in the world.

The bull he was riding is named Hard Times.

Last weekend Lowe posted video on his Twitter account of one his bull rides.

RELATED: Mason Lowe Remembrance Ceremony Planned For Wednesday Night

PBR and NWSS announced a website to donate to Lowe’s family.