I ran the numbers on this a while ago, and Metro averages about one fatality per year (looking at the last ten years, but they're clumped, so this is not necessarily accurate) and that makes them about 10x safer than cars for the equivalent number of passenger-miles. So yes, they're safer, but they wouldn't need to be killing people every day to approach the level of cars, once a month would do it.

What's worrying is that there are a lot of non-fatal incidents (fires and such) which avoid killing people purely by luck. If they don't take action, those are going to start killing people more frequently.

Thankfully they are taking action, finally. Unfortunately that action is going to involve some pretty major shutdowns over the next year.