Yes and no. Sure on purely the face of it there is a much bigger gap before they're underwater, but that's because the preferred shares carry some nice benefit

Yes and no. Sure on purely the face of it there is a much bigger gap before they're underwater, but that's because the preferred shares carry some nice benefits: preference, multipliers and possibly some control of the company. Marking down the value of the preferred shares implies that those benefits aren't worth what they paid a premium for, which means that common shares are also less likely to be worth anything, since they generally get paid out only if the preferred shares are converted or if there is money left over after preferred shares get paid off.