Somebody committed arson in my dorm once...
This individual left newspapers on top of the ranges in several suites, including the one next door to mine and the one above mine, and turned the burners on. S/he obviously knew the night watchmen's patrol times - they used to come through at 1am and the fires were started around 1:15.
The papers caught fire, the alarms went off, we all evacuated (brrr!), and the firefighters went in and put out the fires. Thankfully, the fires didn't spread.
There were similar attacks in at least two other dorms on campus, attributed to the same person - who was never caught