Bricked Nexus 6

Hi guys -

I'm somewhat a newbie here. I think I have bricked my Nexus 6. I had root and an unlocked bootloader. I had Chroma riom installed and was trying to go back to stock rom, unrooted with locked bootloader and through TWRP i deleted everything, including the OS I believe. So now my phone is locked on the Google startup screen (unlocked bootloader) . Suggestions?

Thanks -

John