First...

First ambulance call in the Valley: 12:04
First fire: 12:06
First traffic accident in the Valley: 12:50 (in Metro's Jurisdiction)
First Accident with injury: 12:17 (NHP Jurisdiction)
First Drunk thrown in jail: probably 12:00
First Shooting at 2:21 AM
Update:  By 1:50 AM, there have been 12 ambulance calls just on the Strip on Las Vegas Blvd.