One final explosion, though, occurred much later than the others did.

Ten minutes later they were set free when a second explosion occurred.

They had just left the school when the explosions occurred, officials said.

There's no way the explosion could have occurred at the Point.

A short time later, the explosion occurred, the reports said.

The explosion occurred about an hour before the store was to close.

The explosion occurred several minutes after a class of school children had passed through the area.

But in my head it was as though an explosion had occurred.

The building can be on fire, or an explosion may occur.

The explosion occurred on May 11, 2013 at about 14:15.