# NTSB Incident DEN99IA154
> **Balloon Works FIREFLY 9** · 1999-08-11 · HARTSEL, CO, USA · NONE
## Event
- **NTSB number:** DEN99IA154
- **Event ID:** 20001212X19481
- **Type:** Incident
- **Date:** 1999-08-11
- **Location:** HARTSEL, CO, USA
- **Coordinates:** 39.019771, -105.800933
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 6
- **Total aboard:** 6
## Aircraft
- **Make:** Balloon Works
- **Model:** FIREFLY 9
- **Registration:** N2570E
- **FAR Part:** 091
- **Engines:** —
- **Damage:** MINR
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

Total failure of the deflation line due to heat damage (as evidenced by glazing), most likely caused by the improper use of the flight controls (burner system) by person(s) unknown.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=DEN99IA154) · AI Analytics · CC0 1.0*