A question on standard airline security

I haven’t been able to find an answer to this question, so I’ll throw it out to the class.
In yesterday’s LAX shooting incident, the attacker was himself shot not by LAX security, nor by the LAPD — but by an El Al security officer, who we later found out is actually the head of security for El Al at LAX.
The question is this: Are most airline security personnel armed? Or is El Al unusual in having its own personnel carry weapons?
Stated another way: Would the outcome of this incident have been different if the shooter decided to open fire at United’s ticket counter?
Also: Martin Devon, in between his deeply impressive efforts to take up the slack in Glenn’s absence, points to a (possibly unreliable) report from Debka indicating that the shooter is indeed a Muslim extremist.