Cable news networks clocked enormous ratings increases yesterday when a married couple gunned down 14 at a holiday party in San Bernardino, California, killing 14 and injuring another 21, fled in an SUV and died in a hail of bullets when police caught up to them.

Across 2 PM ET Wednesday to 1 AM today, over which time the drama and careful investigation of the killers’ house unspooled,  Fox News Channel logged an average of 3.8M viewers. That audience is 129% bigger than the network experienced same day last week on Wednesday across those hours.grab5

CNN, meanwhile, logged a whooping 280% increase, to 2.6M viewers, compared to the previous Wednesday.  MSNBC averaged 1M viewers across those hours, a 111% increase vs. same day, same hours last week.

Similar story among the 25-54-year-old viewers the cable news nets target. FNC logged 958K news-demo viewers, which is 212% better than same day last week.  Here too, CNN  scored the biggest percent gain: 280%, to 2.6M news-demo viewers. MSNBC averaged 223K viewers in the age bracket, which is 99% better than the network did same time last Wednesday.

In primetime, FNC led with 5.1M viewers, CNN posted 3.7M and MSNBC 1.4M viewers.