1.   Pemex blamed the accident on a propane leak and said the fires were substantial.

2.   Pemex blamed the explosions on a propane leak.

3.   Pemex said a propane gas leak was to blame.

4.   A propane leak caused the explosion, Carlson said.

5.   An apparent propane leak triggered explosions at a gas-processing plant, propelling fireballs and smoke into the sky.

6.   He said the explosion was caused by a propane gas leak that was somehow ignited.

7.   Investigators determined the explosion was caused by a propane gas leak that was somehow ignited, Carlson said.

8.   It was caused by a propane gas leak, Pemex said.

9.   While the search for bodies has ended, firefighters said they will stay on the site to decontaminate the area following diesel and liquid propane gas leaks.