TULSA, Oklahoma - Tulsa Mayor Dewey Bartlett said early warning help prevent more devastation to the city and its residents as a tornado touched down Wednesday night. Crews are assessing the damage as the sun rose Thursday morning.

"The downed power lines are always a very significant problem," Bartlett said. Public Service of Oklahoma crews are working in the areas to make it safe for residents and emergency services responders.

The mayor said members of Tulsa's emergency management system got into place several hours ahead of time. Personnel made immediate determinations of when the sirens went off and where to respond first.

"We had a very, very good warning system," he said. "Early warning always helps, and in this case, we provided that and people got to a safe place."

Seven people have been reported injured and thousands have been without power.

Bartlett said one improvement that could be made was evident after the tornado, when a deadly fire broke out at 51st and Peoria Tulsa Thursday morning. Though firefighters responded prompted, it took a while to get power shut off the apartment complex because of electrical outages in other areas.

One firefighter was injured by an electrical shock, but he's expected to be OK.

"When we have a very difficult event like a tornado, there are always other things that happen in the city," he said. 

Tulsa Fire Department Tweeted that many of the same firefighters that responded to the tornado area worked the two-alarm fire a short time afterward.