Need Good Triggers for Timer

How do I make a timer for counting remaining seconds for reviving heroes?
I am making a map and I found it difficult creating triggers on reviving heroes...
I make triggers this way: The event: A unit dies runs the trigger with a countdown timer for reviving hero; then, if that timer expires I let the hero revive using the trigger expire timer of reviving hero. This one works IF ONLY ONE HERO DIES but if, only for a second, another hero dies, the timer that I have started is shown and also the current timer and both have same value. I mean, there are already 2 timer window shown. and when another one dies, another timer will be shown while the other timers remain visible. Then, when the timer expires, only one timer is hidden while the other two is still visible...

What I want is to have a timer for each hero when they die, even if they die at the same time.

What is the correct trigger for this...