Silicon Image 3124 RAID Rebuilding

I have a Silicon Image 3124 SATA RAID controller with two 1TB drives mirrored as my "M" drive. Right now, my entire "M" drive is missing from Windows Explorer. When I get into the SATARAID5 Utility, I can see both drives, one on Channel 2 and one on Channel 3. Channel 2 shows "931.51 GB Available". This text is inside the grey box and below it. Channel 3 is highlighted in pink and shows 931.51 GB Mirrored inside the box, but underneath the box, it shows 0.0 MB Available. I don't know what this means. When I click on the RAID Group link, all that's not greyed-out is "Create RAID Group". These two disks were already a RAID Group, but I guess they aren't any more. If I follow through with the Create RAID Group command, will I lose all my data? Does the right, pink, drive with 0.0 MB Available mean this drive isn't functioning?

Thanks in advance for any help you can provide with how I can get my mirrored drives online again.