NBC's "Trauma" flatlined Monday in its second week on the air, while overall the nets took a hit as a strong "Monday Night Football" matchup on ESPN impacted viewership.

After a weak debut last week, "Trauma" (1.8/4, 5.5 million viewers) fell 18 percent in its second broadcast and finished a distant fourth in its 9 p.m. timeslot. The medical drama actually ranked fifth in adults 18-34, losing to CW's "Gossip Girl" in the demo.

While "Trauma" was a huge promotional priority for the Peacock pre-season, and a favorite of executives there, the series now has to be considered on life support following this performance. NBC might be patient, however, and see if the show perks up next week, when the "Monday Night Football" competition may not be as intense.

At 8 p.m., "Heroes" (2.3/6, 5.4 million) dropped eight percent to its lowest ratings ever.

The Jay Leno/Future of Television Watch, Sponsored by "Late Show with David Letterman": 1.4/4, 4.3 million. Tied all-time low in demos. Roughly 800,000 viewers below Leno's "Tonight Show" average. No boost from the Letterman scandal (not that anyone really thought there'd be.)

Over at CBS, comedies still ruled but everything got clipped by the NFL. Among adults 18-49, "How I Met Your Mother" was down the least (just 6 percent); "Big Bang Theory" suffered the most (off 15 percent), but still built on its lead-in.

Newcomer "Accidentally on Purpose" (2.8/7, 7.22 million) was down 10 percent in the demo, a lackluster but hardly alarming number.

Fox didn't avoid the NFL crush, with "House" (5.1/13, 13 million) cooling 12 percent at 8 p.m. The good news: "Lie to Me" (3.0/7, 8.1 million) was up a tad from last week (though a "House" overrun to 9:01 may have lifted it a bit).

We're going to avoid analyzing ABC's numbers since two big affiliates pre-empted regular Alphabet programming in order to carry the big football game. So while "Dancing with the Stars" and "Castle" seemed impressive in the fast nationals, that could change in a few hours.