"We were alerted to a dead Falcon in Downtown Berkeley. And when our team members went to go find it, they found it and it turned out it was Grinnell. And looks like he was probably hit by a car," said Sean Peterson, Cal Falcons Ornithologist.
Grinnell's untimely death comes after Annie just laid two eggs.
"And it's just really a tragic, tragic loss right at the start of the breeding season."
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Peterson says there are a couple of options to explain Grinnell's death.
"The first is that he might have been trying to hunt a pigeon or something that and he just moved too low and happened to end up in the street. Random bad luck," he said.
But he says peregrine falcons are pretty maneuverable and fast birds, so that's not super likely.
"Another option is that he was potentially in a conflict with another bird and was forced onto the ground by another bird. And that's how he ended up in the street. It's really hard to say."
Just last month, Annie went viral after she disappeared for weeks. The worry was she left her longtime mate Grinnell for good.
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But Annie eventually returned to her nest, their kids---and Grinnell.
Now, one day after Grinnell's death, Peterson says a new male Falcon has courted Annie.
And she has been receptive.
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According to Cal Falcons scientists, in a tweet on Friday, the new male falcon has spent the night with Annie, appeared interested in incubating the eggs and performed multiple courtship displays with Annie.
Peterson says he has received a report that Annie and this new male already mated.
The next step with Grinnell -- a toxicity screening. And he may end up at the Museum of Vertebrate Zoology at Cal.
They are still working on memorial plans to honor him.
What's next in this continuing saga? Which seems to be like a reboot of "Falcon Crest." But with real falcons.
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Watch the full interview in our video player above.