The blast was most likely caused by a natural gas leak.

The cause of the gas leak was under investigation yesterday.

"I assume the police looked into the possibility of a gas leak."

They think maybe there's been a gas leak or something.

Officials said the blast was probably caused by a gas leak.

It was the second gas leak at the mill in recent days.

I know what to do to find a gas leak!

The officials said a gas leak was the most likely cause but did not rule out other theories.

Later reports state that the explosion was due to a gas leak.

Others could lead to gas leaks or water damage if they're not done properly.