From e665965c6070d0fa6523e3beab6738bc4e586b39 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Fri, 19 Nov 2021 15:37:25 -0600
Subject: [PATCH] Ensure particles lost during event_calculate_xs are
 terminated

---
 src/simulation.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/simulation.cpp b/src/simulation.cpp
index e29c4da25..35d76ed87 100644
--- a/src/simulation.cpp
+++ b/src/simulation.cpp
@@ -679,6 +679,8 @@ void transport_history_based_single_particle(Particle& p)
 {
   while (true) {
     p.event_calculate_xs();
+    if (!p.alive())
+      break;
     p.event_advance();
     if (p.collision_distance() > p.boundary().distance) {
       p.event_cross_surface();