naa, 1 axle.. if you were going to replace for better parts, you'd have done both.
My first response was going to be "whapped a curb"
But this is a rwd s2k. Rear wheel could have had a bearing failure, causing the whole system to suddenly jam.. that could jolt things hard enough to screw the trans. Or, on the same note, transmission could have seized suddenly (lost a tooth, then jammed the tooth between gears causing instant and sudden failure) which could screw with the rest of the system.