Clashing Rocks & Cave In

[bigb103]

In reading Clashing Rocks spell it reads, "If the target fails a Reflex Saving Throw, it is also buried under the resulting rubble as if by a cave-in." How large is the rubble that is tacked on top of the characters that failed their saves. I'm needing to know so I can figure out how long it will take for them to dig out of the rubble.

[Quandary]

There is a specific rule for it, in Environment Chapter: Dungeon Terrain:
(inserted via Errata in 4th printing or so of Core Rule Book, along with similar rules for Avalanches)

Quote:

Characters take 1d6 points of nonlethal damage per minute while buried. If such a character falls unconscious, he must make a DC 15 Constitution check each minute. If it fails, he takes 1d6 points of lethal damage each minute until freed or dead.

Characters who aren't buried can dig out their friends. In 1 minute, using only her hands, a character can clear rocks and debris equal to five times her heavy load limit. The amount of loose stone that fills a 5-foot-by-5-foot area weighs 1 ton (2,000 pounds). Armed with an appropriate tool, such as a pick, crowbar, or shovel, a digger can clear loose stone twice as quickly as by hand. A buried character can attempt to free himself with a DC 25 Strength check.