A 987 top has 2 arms (1 on ea side) that support the top and control the up / down movement. The metal sound you heard was probably the arm on the right breaking and flinging itself loose. There's a plastic cap on the end of the arm that's designed as the weak pt and is supposed to break when something gets out of line. However, the next weak link is the arm of the turnbuckle and it can bend if the end cap doesn't break. These arms are attached to the metal arches of the clamshell and the inner body of the car.
DON'T run the motor to open or close the top if an arm has broken. The top won't want to move but the transmission running the top will still try. It's made up of plastic gears that will grind to smitherines if the top isn't moving but the trans is. Raise & lower the top by hand until you get the arm situation figured out. When opening by hand, be careful and watch the clamshell to be sure it's not bending into a pretzel.
The good news is you can buy the end caps if they're broken or an entire arm. If the right arm has broken and needs replacing, be sure to check the left arm for straightness. The left can bend because it's trying to do all the work of both arms when the right one broke.
The right arm had broken on an 09 Box S I had as a Wheeler Dealer car. I fixed the right arm but the clamshell wasn't closing / fitting properly. That's when I checked the left arm, which was found to be bent. Here are some pics of the arms - 1 good, 1 bad. The pic is of the bent left arm I'd removed.
