On Monday, with support from the International Alliance of Stage Employees union, the crew of the NBC series walked off the set in an effort to unionize.
"This is a top-rated prime-time television show, and the crew remains unified," IATSE international President Matthew D. Loeb said in a statement. "The strike is the result of a unanimous decision by members of the production crew that they get a contract similar to others covering these types of productions, and we are resolute in getting it for them."
Wages and working conditions are not the issue, sources told THR; pension and health benefits are.
The show has about 50 crew members (some are union members) and all voted to walk off the production, the trade paper reported.
Reps for the NBC series did not respond to TVGuide.com's after-hours e-mails.