1.   A cigarette lighter caused an explosion in hydrogen balloons at a commercial promotion, injuring dozens of middle school students and teachers, according to a report Thursday.

2.   Both pilots were killed when a helicopter gunship shot down their hydrogen balloon during an international race on Tuesday.

3.   Both men were killed when a helicopter gunship shot down their hydrogen balloon on Tuesday, the fourth day of an international race.

4.   Suwat said he would set up a committee to study the issue, but said his initial reaction was that hydrogen balloons should be banned, the Post reported.

5.   The boxes, believed to have been manufactured in Philadelphia, are normally released from huge hydrogen balloons at great heights, he said.

6.   The hydrogen balloons were in the annual Gordon Bennett race, a contest to see which balloon can fly the farthest.

7.   Their balloon was forced down Tuesday in Belarus, the same day a military helicopter shot down the first American hydrogen balloon, killing Fraenckel and Stuart-Jervis.

8.   Two pilots were killed when a helicopter gunship shot down their hydrogen balloon during an international race on Tuesday.

9.   Planes and hydrogen balloons equipped with small explosives charges can also be used to disperse the chemicals.