[freeandfreezing]

Emergency deflation in flight is done by pulling to top vent control line. That opens the top of the balloon, causing it to deflate. Obviously doing that at a significant altitude is a bad idea, but it is often done at low altitude to land in difficult circumstances, or to avoid a much more dangerous collision. For some balloons the same vent can be used for altitude management when opened slightly for brief intervals.

For an FAA safety guide on the topic see:

Powerlines and Thunderstorms Balloon Safety Tips

[CFIIIMEIATP737]

Thank you! and one last question. We carry portable fire extinguishers in the cockpit and the passenger compartment. Do balloons carry fire extinguishers? You would think for commercial use it would be a requirement.