Chicago 911 call center facts

On Friday 9/20/2008 several of us participated in a tour of our city's 911 call center - or OEMC as it's officially called (Office of Emergency Management and Communications). This tour was organized through the August 2008 CAPS meeting. Following are some facts about the center and it's activity that you may find interesting:

Chicago 911 Facts - OEMC Tour. 9/20/2008

OEMC building has been built to stand up to any national disaster. The building’s pylons go down 150 feet to bedrock and building is built to withstand a 150 mph wind. The building system takes all the city’s 991 calls (24 hours – 7 days per week) and can view all the city’s police cameras. The police cameras can also be viewed in the local police district station.

In the center of the communication center to the right, there are 44 police emergency computer stations for call takers. To left are 27 fire/safety emergency computer stations for call takers. Once a call taker has defined the emergency need, it is passed to either the police or fire/safety dispatchers. The police dispatchers are located to right of the police emergency call takers and the fire/safety dispatchers are located to left of the fire/safety emergency call takers. Once an emergency event is dispatched its status is shown on very large screen in the center of the room where all the active emergency events are displayed until they are closed out.

Chicago’s 311 system (24 hours – 7 days per week) is housed in a different facility and is completely independent of 991. The 331 system is a “one-stop shopping center for access to all city services and non-emergency police reports. If you need a copy of a police report or reporting a crime that occurred in the past, you should call 311 not 911.

Chicago normally has 5.4 million 911 events in a year and is second largest system with New York being the largest. Los Angeles, CA normally has 4 million events in a year.
The Chicago system has language interpretation service that can interpret more than 140 languages and dialects when it is need in real time.

On a daily basis:
Slow day 15,000 to 18,000 events per day
11 to 12.5 events per minute (evenly spaced through the day)
20 to 35 events per minute (uneven distribution)

Heavy day 25,000 to 40,000 events
18 to 28 events per minute (evenly spaced through the day)
40 to 100 events per minute (uneven distribution)

Police are dispatched on a 911 event on a priority basis as follows:

Priority 1: Reported event involves the threat of personal harm to someone.
Priority 2: Reported event is just happening.
Priority 3: Everything else (drug cases are a priority 3 but they go directly to
tactical teams handling the drug cases.).

Calls from a landline will show the source of the call on the 911 computer. Calls from Mobile phone give the 911 operator no exact location of where the caller is located. 52 % of the 991 calls come from Mobile Phones. So they need to know where you are calling from to help you.

911 need specific information on the event so that the police unit is properly dispatched. The police unit must have sufficient information on the event so that they do not put themselves needlessly in harm’s way due to the lack of information on the dangers involved in the event. Police units are normally dispatched in less than a minute from first taking the 911 call.

Police may not respond right away to a 911 event for the following reasons:

A tactical police unit may already be on the scene in the process of gathering evidence for arrests and the dispatcher has waved off the responding police unit.

All available police units are already assigned to higher priority calls and it has to wait until a unit is available for this event.

Incomplete information or a mistake in the information that has been supplied to the police unit makes it impossible to find the problem.

Police unit observes the reported 911 event and in their opinion it does not meet the rules for stopping an individual.