(CNN) A Florida state agency said Friday it has opened a probe to find out why a roller coaster derailed at an amusement park Thursday night in Daytona Beach.

The accident sent two riders plunging 34 feet to the ground and left two others dangling in one of the ride's cars, the Daytona Beach Fire Department said. They were among 10 people on the Sand Blaster ride at the Daytona Beach Boardwalk.

"First and foremost, we're concerned about the individuals who were injured last night. Their well-being and recovery is of the utmost importance," said Jennifer Meale, spokeswoman for the state's Department of Agriculture and Consumer Services.

Meale said the ride had passed inspection the morning of the accident. It was inspected again after the accident and failed due to deficiency listed as "structural integrity: other."

She said the ride failed two previous inspections in May due to multiple deficiencies, but all of the problems had been corrected before Thursday's accident.

Read More