A Blue Origin New Glenn rocket experienced an anomaly during a ground test known as a hotfire Thursday, the company shared on X.

Axar.az infoms, citing CNN, video captured from Cape Canaveral Space Force Station in Florida Thursday evening appears to show a rocket exploding on its launchpad.

“All personnel are accounted for and safe,” Jeff Bezos, Blue Origin’s founder, said in a separate X post. “It’s too early to know the root cause but we’re already working to find it. Very rough day, but we’ll rebuild whatever needs rebuilding and get back to flying. It’s worth it.”

New Glenn’s fourth mission was intended to carry 48 satellites to join Amazon Leo’s broadband constellation.