If you're passing by the T.T.C. subway yard between the Dundas West and Keele subway stations Thursday and you see lots of smoke and lots of commotion, don't panic and don't call authorities.

They'll already be there.

The Red Rocketeers will be conducting an emergency simulation at the T.T.C. yard between 9:30am and noon and they're determined to make it look as real as possible. Thick white 'theatrical' smoke will be emanating from the area, but it's fully controlled and there won't be any fire. 

The purpose: to help train Toronto firefighters how to respond to emergencies inside a tunnel.

At least 30 people will be involved in the exercise, which will allow personnel to practice using subway rescue equipment and go over evacuation procedures. Normal train service won't be affected and no one will be in any real danger.  

The T.T.C. holds such readiness procedures at least 20 times a year and with the sensitivty to terror attacks, officials want riders and the public to know it's only a test.