The Temple Institute: In-Depth Temple Study: The Three Woodpiles
 
The Three Woodpiles (continued)

In the beginning of the First Temple period, a fire descended from heaven to the altar. The fire atop the altar during that era was described as being as "strong as a lion" - it burned with great strength. However, the woodpile was still kindled with twigs, from which the fire spread to the entire woodpile. This is according to the Halacha * which states that fire must be brought by human agency, despite the fact that fire had fallen from heaven. Source: Yoma 21:B) 
Contents:   Part I,    Part II,    Part III,    Part IV,    Part V,    Part VI,    Part VII