https://www.cnet.com/news/senators-want-faa-to-ground-boeing-737-max-after-ethiopia-crash/

"Until the cause of the crash is known and it's clear that similar risks aren't present in the domestic fleet, I believe all Boeing 737 Max 8 series aircraft operating in the United States should be temporarily grounded," wrote Feinstein in her Monday letter, which was sent to the FAA. "This aircraft model represents only a small fraction of the domestic fleet, and several other countries have already taken this important step, including China and Indonesia."

Blumenthal and Romney have echoed similar concerns on Twitter.