Great to see so many replies.
The Captain can order to keep the unsafe exits closed before ordering the evacuation.
"Attention Captain speaking: keep after doors closed, evacuation evacuation evacuation !" would be the announcement in my company.
Even then, people would use the overwing exits, and for sure there would be some injuries.
After the situation is assessed and under control, a reletively fast deplaning via the front doors would probably be my choice, but without forgetting that people starting to run on the runway can easily get injured by the full speed oncoming fire brigade vehicles.
So really, the safest place for them is inside the airplane.
As has been said, it takes a good briefing and a convincing loud voice to prevent passengers in panic from starting their own evac.
"It would have been easy to chew him out for disobeying a mission rule. But we didn't pay these guys to always follow the rules. By intuition and experience, this Commander saved the day. When I later met him, I simply said Thank You Wally".
Flight Director Chris Kraft about W.Shirra's decision not to eject from Gemini something when it failed to ignite properly, even if that was a crystal clear NASA mission rule.