What is the correct mechanics?

All I can tell you is what we were taught to do as an IF in this situation.  Tag both runners, then tell the lead runner he is out. When he steps off, tag him again & you have them both. The trail runner is the out if they both occupy & I do not think the FU is obligated to tell which runner is out.

The base umpire should have made two calls since a play was made on each runner.  Call the following runner out first (by pointing to him while making the out mechanic.)  Then call the lead runner safe is the same manner.  This should be done very deliberately with proper voice and mechanic so that there is no confusion as to who is out and who is safe.

JWC1022 posted:

The base umpire should have made two calls since a play was made on each runner.  Call the following runner out first (by pointing to him while making the out mechanic.)  Then call the lead runner safe is the same manner.  This should be done very deliberately with proper voice and mechanic so that there is no confusion as to who is out and who is safe.

And, use the player's name / number as part of the mechanic. "#44 you are out; #12 you are safe."

All of the above assuming, of course, that the lead runner was not forced from the base.  If he was, then he is out and the trailing runner is safe.  The rest of the mechanics are the same.

Agree with my esteemed brethren on making the effort to prevent ambiguity.

There are times when an umpire should remain silent and let players figure it out, such as a play at the plate where the catcher misses the tag and the runner misses the plate.

However, when an umpire makes a safe call and an out call at the same location, the calls should eliminate confusion, not add to it.  A player who has been called safe or out deserves to know his status.

I agree with U should have made two calls, but order should have been: Safe then out (assuming no force).

One of those rare occasions when zealousness pays off.  Dependent on the timing of all this.  Had both runners just stayed on the bag, then pointing, numbers sure.

Bang bang, might just got ya two easy outs, not blues fault.  

Lead runner knew he got tagged first, so a strong safe signal shoulda, coulda, clued him in.  Then out on the second tag, in turn should have reinforced it. 

Following runner new he was out, why he left the bag.  

Lead left cause he didn't know he was safe.