Sorry to hear that! What the consensus on the best way for someone to avoid this? Immediate vesting if let go? Some predefined severance agreement? 6 mo/12 mo contract? I understand it's a big decision for a startup to hire employee #1, but how can I protect myself in such a future case?
Joining a startup is a risk, period. Part of that risk is that the company (or your job) will be gone in weeks/months/years. However, the upside is usually there. So if you can tolerate the risk, go for it... but always have a plan B.