EXHIBIT 21

SUBSIDIARY LIST

AS OF SEPTEMBER 15, 2008

NAME	STATE	NAMES UNDER WHICH ENTITY DOES BUSINESS
Overall Parent Company
Rural/Metro Corporation	Delaware
Subsidiaries of Rural/Metro Corporation (a Delaware corporation):
Rural/Metro Operating Company, LLC	Delaware
Subsidiaries of Rural/Metro Operating Company, LLC:
Aid Ambulance at Vigo County	Indiana
Ambulance Transport Systems, Inc.	New Jersey
Donlock, Ltd.	Pennsylvania	Rural/Metro Medical Services, Ltd.; Rural/Metro Ambulance, Ltd.
Medical Emergency Devices and Services (MEDS), Inc.	Arizona	MEDS & Logo
Metro Care Corp.	Ohio	Rural/Metro Ambulance
MO-RO-KO, Inc.	Arizona
Multi-Health Corp.	Florida
North Miss. Ambulance Service, Inc.	Mississippi
R/M Partners, Inc.	Delaware
Rural/Metro of Central Colorado, Inc.	Delaware	Aurora Medical Services
Rural/Metro Corporation	Arizona	Rural/Metro Ambulance Service, AMT, Arizona Medical Transport, Tri-City Med
Rural/Metro (Delaware) Inc.	Delaware
Rural/Metro of Greater Seattle, Inc.	Washington	Rural/Metro Ambulance
Rural/Metro of Southern Ohio, Inc.	Ohio	Rural/Metro Ambulance
SW General, Inc.	Arizona	Southwest Ambulance; Southwest Transportation Services; Southwest Medical Services; Tri-City Med
South Georgia Emergency Medical Services, Inc.	Georgia
Southwest Ambulance of Casa Grande, Inc.	Arizona	Southwest Ambulance and Rescue of Arizona; SWARA
Southwest Ambulance of New Mexico, Inc.	New Mexico
Southwest General Services, Inc.	Arizona	SW General Services; Southwest Medical Billings Services

The Aid Company, Inc.	Indiana
Subsidiaries of Rural/Metro Corporation (an Arizona corporation):
E.M.S. Ventures, Inc.	Georgia	Rural/Metro Ambulance
EMS Ventures of South Carolina, Inc.	Delaware
Medi-Cab of Georgia, Inc.	Delaware
Medstar Emergency Medical Services, Inc.	Delaware
Mercury Ambulance Service, Inc.	Kentucky	Rural/Metro Alternative Transport Services; Rural/Metro of Bullitt County; Rural/Metro of Louisville I; Rural/Metro of Louisville II; Rural/Metro Tri-County
R/M Management Co., Inc.	Arizona	Arizona Medical Transport; Red Van; Southwest Transportation Services
RMC Corporate Center, L.L.C.	Arizona
RMC Insurance Ltd.	Barbados
Rural/Metro Corporation of Florida	Florida	Rural/Metro Ambulance
Rural/Metro Corporation of Tennessee	Tennessee	American Medical Transport
Rural/Metro Fire Dept., Inc.	Arizona	Rural/Metro Fire Dept.; Rural/Metro Fire Department
Rural/Metro of California, Inc.	Delaware
Rural/Metro of Central Alabama, Inc.	Delaware
Rural/Metro of Nebraska, Inc.	Delaware
Rural/Metro of New York, Inc.	Delaware
Rural/Metro of Ohio, Inc.	Delaware
Rural/Metro of Oregon, Inc.	Delaware
Rural/Metro of Texas Holdings, Inc.	Delaware
Sioux Falls Ambulance, Inc.	South Dakota
The Aid Ambulance Company, Inc.	Delaware
W & W Leasing Company, Inc.	Arizona
Subsidiaries of Aid Ambulance at Vigo County, Inc.:
Rural/Metro of Indiana II, L.P. (99%)	Delaware
Subsidiaries of Ambulance Transport Systems, Inc.:
Keefe & Keefe Ambulette, Ltd.	New York
Keefe & Keefe, Inc.	New York
Subsidiaries of Keefe & Keefe, Inc.:
Multi Cab Inc.	New Jersey

Multi-Care International, Inc.	New Jersey
Subsidiaries of MO-RO-KO, Inc.:
Southwest Ambulance of Tucson, Inc.	Arizona	Kord’s; Rural/Metro Ambulance
Subsidiaries of North Miss. Ambulance Service, Inc.:
Rural/Metro Mid-South, L.P. (99%)	Delaware
Subsidiaries of R/M Partners, Inc.:
Rural/Metro Mid-Atlantic II, Inc.	Delaware
Subsidiaries of Rural/Metro Mid-Atlantic II, Inc.:
Mobile Medical Transportation, Inc.	Maryland
Subsidiaries of Mobile Medical Transportation, Inc.:
Choice American Ambulance Service, Inc.	Virginia
Subsidiaries of RMC Insurance, Ltd.:
RMC Corporate Center, L.L.C. (99%)	Arizona
Subsidiaries of Rural/Metro Corporation of Florida:
Rural/Metro of North Florida, Inc.	Florida
Subsidiaries of Rural/Metro Corporation of Tennessee:
R/M of Tennessee G.P., Inc.	Delaware
R/M of Tennessee L.P., Inc.	Delaware
Subsidiaries of R/M of Tennessee G.P., Inc.:
Rural/Metro Mid-South, L.P. (1%)	Delaware
Rural/Metro of Tennessee L.P. (1%)	Delaware	Rural/Metro Ambulance, L.P.
Subsidiaries of R/M of Tennessee L.P., Inc.:
Rural/Metro of Tennessee, L.P. (99%)	Delaware
Subsidiaries of Rural/Metro of California, Inc.:
Rural/Metro of San Diego, Inc.	California
Subsidiaries of Rural/Metro of San Diego, Inc.:
San Diego Medical Services Enterprise, LLC (50%)	California
Subsidiaries of The Aid Ambulance Company, Inc.:

Rural/Metro of Indiana, L.P. (1%)	Delaware	Rural/Metro Ambulance
Rural/Metro of Indiana II, L.P. (1%)	Delaware
Subsidiaries of Rural/Metro of Nebraska, Inc.:
Eastern Ambulance Service, Inc.	Nebraska
Subsidiaries of Rural/Metro of New York, Inc.:
Corning Ambulance Service Inc.	New York
Eastern Paramedics, Inc.	Delaware	Rural/Metro Medical Services
LaSalle Ambulance Inc.	New York	Rural/Metro Medical Services
Rural/Metro of Rochester, Inc.	New York	Rural/Metro Medical Services
Towns Ambulance Service, Inc.	New York	Rural/Metro Medical Services
Subsidiaries of Eastern Paramedics, Inc.:
Rural/Metro of Brewerton, Inc.	New York
Subsidiaries of Rural/Metro of Rochester, Inc.:
Beacon Transportation, Inc.	New York	Rural/Metro Medical Services
National Ambulance & Oxygen Service, Inc.	New York	Rural/Metro Medical Services
Subsidiaries of Rural/Metro of Ohio, Inc.:
Gold Cross Ambulance Services, Inc.	Delaware	Rural/Metro Ambulance
Rural/Metro of Central Ohio, Inc.	Delaware	Rural/Metro Ambulance
Rural/Metro of Northern Ohio, Inc.	Delaware	Rural/Metro Ambulance; Hess Ambulance Service; Physician’s Lifeline, Inc.; Physician’s/Medic Transport, Inc.
Subsidiaries of Gold Cross Ambulance Services, Inc.:
Gold Cross Ambulance Service of PA., Inc.	Ohio	Rural/Metro Ambulance
Subsidiaries of Rural/Metro of Oregon, Inc.:
Valley Fire Service, Inc.	Delaware	Rural/Metro Fire Department; Valley Fire Service
Subsidiaries of Rural/Metro Texas Holdings, Inc.:
R/M of Texas G.P., Inc.	Delaware
Rural/Metro of Arlington, Inc.	Delaware
Rural/Metro of Texas, Inc.	Delaware	Rural/Metro Ambulance
Subsidiaries of R/M of Texas G.P., Inc.:

Rural/Metro of North Texas, L.P. (1%)	Delaware	Rural/Metro Ambulance
Rural/Metro of Texas, L.P. (1%)	Delaware	Rural/Metro Ambulance, L.P.
Subsidiaries of Rural/Metro of Texas, Inc.:
Rural/Metro of North Texas, L.P. (99%)	Delaware	Rural/Metro Ambulance
Rural/Metro of Texas, L.P. (99%)	Delaware	Rural/Metro Ambulance
Subsidiaries of Southwest Ambulance of Casa Grande, Inc.:
Southwest Ambulance and Rescue of Arizona, Inc.	Arizona	Southwest Ambulance and Rescue of Arizona; SWARA
Subsidiaries of The Aid Company, Inc.:
Rural/Metro of Indiana, L.P. (99%)	Delaware

LIMITED PARTNERSHIPS

NAME	STATE	NAMES UNDER WHICH ENTITY DOES BUSINESS
Rural/Metro Mid-South, L.P.	Delaware
Rural/Metro of Tennessee, L.P.	Delaware	Rural/Metro Ambulance
Rural/Metro of Indiana, L.P.	Delaware
Rural/Metro of Indiana II, L.P.	Delaware
Rural/Metro of North Texas, L.P.	Delaware	Rural/Metro Ambulance
Rural/Metro of Texas, L.P.	Delaware	Rural/Metro Ambulance

LLCS

NAME	STATE	NAMES UNDER WHICH ENTITY DOES BUSINESS
RMC Corporate Center, L.L.C.	Arizona
Members: RMC Insurance Ltd. (99%)
Rural/Metro Corporation, an Arizona corporation (1%)
Medical Transportation System, LLC	Maryland
San Diego Medical Services Enterprise, LLC	California
Member: Rural/Metro of San Diego, Inc. (50%)
Southwest General Services of Dallas, L.L.C.	Delaware