[spycatcher]

I think the grenade heat is fairly localized. No doubt they all could have died had they been trapped.

[null and void]

The radius of the burst is approximately 6 meters, but fragments of the plastic body occasionally fly as far as 27 meters. Effective portions of the agent may be carried as far as 75 to 100 meters downwind. Personnel using these grenades should wear protective gas masks.

The tent is probably no larger than 3 meters on a side. I bet the men weren't sleeping in gas masks...