This from Dennis McGuire, Jr.

Starting in October, Lake County, Indiana fire departments and police departments will all be dispatched by one center. Motorola Solutions, Inc. and AT&T have been working on this for a year. Not all of the fire departments went online at once, but at the end of October all departments will be under the new center. I believe the center is located in Crown Point, Indiana. The numbering system is as follows:
00     = Stations
01-09= Officers
10-19= Engines
20-29= Trucks
30-39= Rescues
40-49= Tankers
50-59= Specialty Units
60-69= Ambulances
70-79= Brush trucks
80-99= Individual department members
The following is a partial list of the departments and their assigned number(s):
1200-Cedar Lake
1500-Crown Point
1800 to 2100-Dyer
2500-East Chicago
3100 to 3300-Griffith
4100 to 4800-Hammond
5100 to 5200-Highland
5300 to 5600-Hobart
5800-Lake Dale
5900-Lake Hills
6100-Lake Ridge
6300 to 6400-Lake Station
6600 to 6800-Lowell
6900-New Chicago
7000 to 7400-Merriville
7500 to 7700-St. John
7800 to 800-Schererville
8500 to 9900-Gary