Investigators believe the device inside is consistent with a smoke bomb or smoke grenade.
Detroit won for only the second time in nine shootouts this season and came away with their fifth consecutive victory overall.
In the six games Mrazek has played in January, five times he has limited opponents to two goals or fewer.
Zetterberg’s hat trick capped an impressive Detroit comeback …
Gustav Nyquist, Kyle Quincey and Tomas Tatar scored in the first period for Detroit, chasing Nashville goalie Carter Hutton from the game after only one save.
Petr Mrazek made 25 saves and improved to 3-0 in four career appearances against St. Louis.
There are traits that most Stanley Cup winners tend to have in common …
Pittsburgh Penguins goaltender Marc-Andre Fleury was selected to the All-Star game for the second time on Wednesday.
Darren Helm, Gustav Nyquist and Tomas Tatar scored for the Red Wings, who have won three of four. Kyle Quincey had two assists.
Howard had been allowing an average of 2.11 goals, fourth in the league, and had been selected for the All-Star Game.