The team was informed of the incident as they were boarding a plane for Cincinnati, where the Cowboys will play the Bengals in a game with significant playoff implications for both teams.
Brent allegedly was driving under the influence of alcohol when the car he was driving struck a curb while at high speed and flipped at least once, according to Irving, Texas, police spokesman John Argumaniz.
Brown was the only other passenger in the car with Brent and he was pronounced dead at an area hospital. Brent was arrested at 4:14 a.m. Saturday.
Brent, a seven-round pick by the Cowboys in the 2010 Supplemental Draft, has started five games for Dallas this season.
Cowboys owner Jerry Jones released a statement:
"We are deeply saddened by the news of this accident and the passing of Jerry Brown. At this time, our hearts and prayers and deepest sympathies are with the members of Jerry's family and all of those who knew him and loved him."
It's the second NFL player to be killed in the last seven days. Chiefs LB Jovan Belcher committed suicide in front of Chiefs' personnel Dec. 1 after allegedly killing his girlfriend in suburban Kansas City.
The Steelers play the Cowboys in Dallas in Week 15.