US President Barack Obama speaks about Syria from the Rose Garden at the White House in Washington, DC, on August 31, 2013. (JIM WATSON/AFP/Getty Images)

Expect preemptions as President Obama gives a prime-time address about Syria on Tuesday at 9 p.m. All the broadcast networks (NBC, ABC, Fox, CBS and WETA) will carry the speech, along with the usual cable news channels, including CNN, MSNBC, Fox News Channel and Fox Business Network.

Documentary “American Masters: Billie Jean King” (WETA, MPT at 8), profiling the tennis legend, is reviewed by Hank Stuever on Page C1.

Get the tissues ready for “Hero Dogs of 9/11” (Animal Planet at 8) as three survivors of the Sept. 11 attacks talk about how rescue dogs saved their lives at Ground Zero.

FINALE WATCH: One male dancer and one female dancer are named champions on “So You Think You Can Dance” (Fox at 8), with appearances by guest judges Paula Abdul and Adam Shankman. (Note: Set your DVRs accordingly, as the episode will stop for the president’s speech and then resume afterward, so the show will run well past 10 p.m.).

The top 12 finalists perform in front of Howard Stern, Mel B, Heidi Klum and Howie Mandel at Radio City Music Hall as the season winds down closer to the $1 million prize on “America’s Got Talent” (NBC at 9). (Another DVR note: The show will start as soon as Obama’s speech is over, so it will run past the 11 p.m. end time.)

S ERIES PREMIERE: You knew this was bound to happen — a reality show about bathrooms. On new show “King of Thrones” (Destination America at 10), a team of construction experts transforms old bathrooms into wildly decadent spaces. In the opener, a couple wants their bathroom, which doesn’t even have a door, to be turned into a spa.

SERIES PREMIERE: New docu-series “Snake Salvation” (National Geographic at 9) follows two pastors from Kentucky and Tennessee who lead their respective congregations in the religious “snake handling” ritual, which involves holding a deadly snake above your head.

Actor Billy Crystal and musical guest Sheryl Crow are on “Late Show With David Letterman” (CBS at 11:35).

“The Tonight Show With Jay Leno” (NBC at 11:35) hosts actress Rose Byrne, Donny Deutsch and country singer Jennifer Nettles.

Reality show judge Simon Cowell and model Stacy Keibler are on “Jimmy Kimmel Live” (ABC at 11:35); Gary Clark Jr. performs.

— Emily Yahr