Death from hydrogen gas cylinder blast in IISc Bengaluru

A person was thrown about 20 feet away, hit the wall and died due to suspected hydrogen cylinder blast.  3 others sustained injuries during the incident. 

The window panes and 20 m high roof sheet got damaged.

Small scale hydrogen explosions are made to create shock waves for conducting experiments.

https://www.thehindu.com/news/cities/bangalore/laboratory-accident-at-iisc-kills-one-injures-three/article25671763.ece

https://www.deccanherald.com/city/research-scholar-killed-3-706586.html

Hydrogen balloon fireball injures 140 in Armenia

Balloon fireball injures 140 in Armenia: More than 140 people have been injured after gas-filled balloons exploded at a concert in the Armenian capital ahead of parliamentary polls, officials say.
"The balloons exploded and caught fire after people holding the bunches released them from their hands into the air," a witness told AFP.
From the witness statement, it can be said that the friction between balloons in the bunch while going up could have caused this. As hydrogen can easily diffuse through rubber, it could have caught fire from the friction as the ignition energy for hydrogen is as low as 0.0017 mJ and this could have resulted in bursting of balloons and fireball. One may recall the famous Hindenburg disaster in 1937. Only the quantity of flammable substance differs but reason can be same, that of static charge generated due to friction.
Such incidents were also reported at several places. In an incident, the hydrogen balloons burst in the hands of children who suffered burn injuries.

LINK

Explosion at a nuclear waste treatment facility in France

A blast occurred at 1037 GMT today (Monday 12.09.2011) at Centraco nuclear waste treatment facility in Marcoule, France reportedly during melting of metal scrap. One person was killed, one was seriously burned and 3 others were slightly injured. As reports say, there is no leakage of radioactivity from the site.As per BBC reports, blast happened in a furnace used to burn waste, including fuels, tools and clothing which had been used in nuclear energy production but had only very low levels of radiation. The ingots formed after melting will be stored safely at a designated place. This is an accepted procedure.
Authorities informed that there are no nuclear power reactors at the site. The explosion also is not from waste storage tanks where radiolytic hydrogen formed can lead to explosion if not diluted. It is also not of any explosion that may arise during concentration of waste by evaporation.
Any non-nuclear incident in a nuclear facility can be misunderstood as nuclear explosion. This accident is to be treated as industrial explosion and not as nuclear explosion. If the explosion occurred during melting, one reason can be water reaction with molten metal. But, as per BBC report and other reports, explosion occurred after fire. It is not known the reason for fire which can be due to flammable solvents or due to friction of fine turnings of iron,zircaloy, aluminium, etc in the metal scrap. It is a known fact that dust explosions are possible with fine dust of these metals.
As there is no radioactivity, we have to assume the explosion is non-nuclear of one of the above types.
http://hanlonblog.dailymail.co.uk/2011/09/marcoule-explosion-is-the-tide-of-anti-nuclear-irrationality-on-the-turn-.html
1)  http://www.msnbc.msn.com/id/44483925/ns/world_news-europe/?GT1=43001
2)  http://www.washingtonpost.com/world/europe/french-nuclear-safety-body-says-an-explosion-has-rocked-a-nuclear-plant-in-countrys-south/2011/09/12/gIQAJUkcMK_story.html
3) http://www.thedailybeast.com/cheats/2011/09/12/explosion-kills-one-at-french-nuke-plant.html?obref=obnetwork
4) http://projectavalon.net/forum4/showthread.php?30252-Breaking-Nuke-explosion-in-France