DanCiliske, ChrisSauro, SkyeBerghel, MartinPyne, and MatthewWodrich were sitting outside Sontag when they heard a loud popping noise coming from the direction of Atwood. They sent Dan to investigate, and about 30 seconds later, heard him yelling "HOLY SHIT IT'S A SPARK."
It turned out that, when contractors were working on the sidewalk north of Atwood the previous week, they had left for the weekend without covering a large electrical conduit. Saturday night, the sprinklers on the hill above the sidewalk turned on. The result was sparks about a foot long that made a loud popping noise. (The sprinkler system almost certainly shorted itself out, as the sprinklers were only on for about a minute.)
Skye called the F&M on-call phone (which, at the time, was in the possession of JenniRinker) and was told to call CampSec. Dan called CampSec and told them there was an exposed electrical conduit that was sparking. CampSec sent up an officer who walked into the puddle the conduit was in and effectively said, "yep, there's an exposed wire and water here." CampSec then sent up another 5 officers and called the fire department, who sent 4 fire trucks. (Popular opinion was that it was a slow night.) The firemen then walked over to the conduit, confirmed that there was an exposed wire and water in proximity to one another, and called an electrician.
The electrician took another 30 minutes or so to show up. In the interim, several people (including Laura Poindexter, MattRichman, and StevenBerler) showed up to ask what was going on and why there were 4 fire trucks on campus, and the original observers of the sparks retold the story several times. By the time the electrician actually showed up, there was a group of about 10 people sitting on the sidewalk in front of Atwood drinking beer or tea. The electrician shut off power to the conduit (and the exterior lights on that side of Atwood) to loud cheers.