After more than 30 years, the gas water heater in this light commercial building failed. The tank was still in good shape (as you can see), but the bottom burner had rusted out completely. So, it would not relight and the water was cold.

The most interesting part about this project was that about 2 years ago we had a new furnace installed in this same utility closet. At that time, we told the contractor that we needed a furnace the same size or smaller as the existing one, so we would be able to get the water heater out when "one day" it would fail. That day was last Sunday.
 
Well, it seemed our contractor had no intention of doing it how we asked, but rather how he wanted to do it, and now we had no room and no easy way to pull the old tank out. So, we cut it out using an assortment of sawzall tools. 

A cheap sawzall stripped a gear (fail), and older heavy metal Black & Decker sawzall kept throwing blades (fail), so we bought a new DeWalt 10 amp sawzall and finished the job. The heavy metal long blades did the job, and a new narrow 17" wide tank was installed the next morning.