Ten-year-old SCOTUS Blog has been a go-to authority on the health care challenge since the beginning, which made today its Oscar night, Super Bowl, and Christmas morning all wrapped into one. But on the Internet, success comes with a darker side: server crashes. SCOTUS Blog was prepared. The traffic buildup was already intense on Monday:

500,000 hits so far today.Very grateful.#teamlyle.

— SCOTUSblog (@SCOTUSblog) June 25, 2012

To put that 500,000-in-one-day in context, it had nearly 1 million over the three days of oral arguments this spring. (Other sites were prepping too; just before the decision was handed down, New York Times developer Jacob Harris tweeted a graph showing a huge traffic spike.)

For SCOTUS Blog, preparing meant investing in server upgrades, even if they would only be used for a short burst of traffic.

Here we go. 4 more web servers. 5 bloggers. 2 tech teams. $25k for 20 mins. #SCOTUS #ACA #teamlyle

— SCOTUSblog (@SCOTUSblog) June 27, 2012

Probably more traffic today than in SB’s first 5 years, combined. So grateful; a little scared. #teamlyle #dontcrash

— SCOTUSblog (@SCOTUSblog) June 28, 2012

To help offload the burden, SCOTUS Blog shut down its main site at peak times and redirected visitors to a dedicated page off-server. That was hosted on WPEngine, a server company that specializes in optimized WordPress installations. And the minute-by-minute liveblog was pushed off to CoverItLive, with an embed put on the WPEngine site. The liveblog page had its own special “Sponsored by Bloomberg Law” message in its header.

And for the moment of maximum interest — the seconds after the decision was announced — SCOTUS Blog publisher Tom Goldstein advised they’d be going to Twitter first. “As a purely formal matter, we will ‘break’ the story of the health care decision on Twitter. So you can follow @scotusblog, if you’d like,” he wrote in the liveblog. “But don’t follow us just for that reason, because we will have the news here on the live blog less than 5 seconds later.”

By 9:08 a.m., he said there were already 70,000 people reading the liveblog and that the site had already logged 1 million hits for the day. His guesstimate for the day’s traffic? “My best bet is 250,000 [concurrent liveblog readers] at the time of the decision.” Goldstein kept liveblog readers updated.

9:16 a.m.: “100,000 live blog readers.”

9:29 a.m.: “145,000 on the liveblog.”

9:33 a.m.: “The previous record for our live blog was 100,000, on Monday. The previous record for our daily hits was 500,000, also Monday.”

9:43 a.m.: “218,000”

9:43 a.m.: “We are at less than 1% of our own server capacity. We’ve shifted the principal processing to CoverItLive, which expects it can handle >3 million.”

9:56 a.m.: “FWIW, the count going into 10am is 344,000 contemporaneous readers.”

10:03 a.m.: “1,000 requests to the liveblog per second.”

10:06 a.m.: “520,000 contemporaneous readers.”

At 10:09 a.m., SCOTUS Blog broke the news on Twitter. At this writing, that tweet’s been retweeted 2,927 times and favorited 142 times. (Also, it was accurate.)

10:22 a.m.: “866,000 liveblog readers.”

That’s roughly the city of San Francisco.

From there, SCOTUS Blog switched into analysis, commentary, and smart aggregation of other sites’ analysis and commentary. But the traffic kept coming, if at a slower pace.

1:11 p.m.: “SCOTUSBlog just clipped over 3 million hits!”

2:17 p.m.: “Thanks to everyone for sticking with us this whole time. There are still over 80,000 people following the live blog.”

CoverItLive said it was the second most popular U.S. event they’ve hosted in 2012, behind only ESPN’s NFL draft coverage.

By 2:46 p.m., SCOTUS Blog staffers were ready to celebrate:

Appx 1M simultaneous readers. 3.4M hits so far. Survived one major hacking attack. Got it right. So grateful to all.

— SCOTUSblog (@SCOTUSblog) June 28, 2012

And by 5:09 p.m., they were really ready to celebrate:

SCOTUSblog meetup tonight in DC @ 8pm.District Commons.2200 Penn Ave, NW.#weneedadrink

— SCOTUSblog (@SCOTUSblog) June 28, 2012

Photo of the Supreme Court by Kjetil Ree used under a Creative Commons license.