As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
2-3 MINUTES AFTER TAKEOFF, THE PARAMEDIC, FLIGHT NURSE AND PILOT NOTICED A STRONG FUEL ODOR AND FUEL STREAMING ON THE OUTSIDE OF THE CLAMSHELL DOORS. DECIDED TO RETURN, AND AFTER SHUTDOWN NOTICED THE FUEL CAP WAS UNLATCHED. TRIED SEVERAL TIMES TO SECURE IT, BUT IT POPPED OPEN. ADJUSTED LOCKING MECHANISM.