GA pilot reported taking off over emergency services that were unknowingly on the runway.

Attributes
ACN	1473112
Time
Date	201708
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	PA-32 Cherokee Six/Lance/Saratoga/6X
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	Direct
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 300 Flight Crew Total 1350 Flight Crew Type 100
Events
Anomaly	Conflict Ground Conflict Critical
Miss Distance	Horizontal 2500 Vertical 100

Narrative:

[Airport] emergency services arrived as I was running up for departure; I questioned over unicom whether emergency services were on the active runway and received a reply from a pilot who departed a few moments before me stating that they were not on the active runway. Since I was not able to directly see if they were or were not there I proceeded to takeoff and announced my departure on unicom. After applying power and beginning my take off roll the emergency personnel called in over the radio stating that they were on the runway. By that time I did not have the available distance to abort my takeoff and if I had it may have been more dangerous than continuing the takeoff. I rotated as soon as practical and made a sharp turn to the left to avoid overflying the cars/people on the runway. I made all reasonable attempts to ensure the runway was clear while emergency services made no attempt to announce their position.

Original NASA ASRS Text

Title: GA pilot reported taking off over emergency services that were unknowingly on the runway.

Narrative: [Airport] emergency services arrived as I was running up for departure; I questioned over Unicom whether emergency services were on the active runway and received a reply from a pilot who departed a few moments before me stating that they were not on the active runway. Since I was not able to directly see if they were or were not there I proceeded to takeoff and announced my departure on Unicom. After applying power and beginning my take off roll the emergency personnel called in over the radio stating that they were on the runway. By that time I did not have the available distance to abort my takeoff and if I had it may have been more dangerous than continuing the takeoff. I rotated as soon as practical and made a sharp turn to the left to avoid overflying the cars/people on the runway. I made all reasonable attempts to ensure the runway was clear while emergency services made no attempt to announce their position.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.