All lights go red on inserting new drive

I have a Gen 2 Drobo I’m using with my iMac. 4 bays firewire/USB.
It was set up with 4x3TB drives. The top one went yellow indicating a need for more space.
I replaced it with a new 6TB drive. It flashed for about a week while rebuilding but finally finished.
Then the top light (the one with the 6TB drive now) went yellow again.
I read a couple places that mentioned that sometimes the wrong light goes yellow in this situation and I know I need to replace 2 drives to get access to extra space.
I dismounted the Drobo, took out the second 3TB drive and replaced it with another new 6TB one.
The four lights all flashed RED a few times and then the Drobo went dark.
I tried putting the 3TB drive back in, but I got the same red flash error.

Did I somehow brick this thing?