Hydrogen bottle explosion

This incident invovled a tank which was inside a car parked in a hospital underground parking garage. The tank was supposed to be used for launching a weather balloon. The hydrogen possibly leaked and ignited. Two people were injured and are being treated in the Emergency Department. The explosion damaged at least three other cars in the parking garage.
The parking garage does not appear to have sustained any structural damage.

Authorities believe the explosion was accidental, which means that an act of terorism or crime was excluded. Nevertheless, transporting compressed hydrogen in a private car, i n absence of permission and safety measure, was an act prohibited by law.

cylinders

Two people were injured and treated in the hospital emergency department. One is listed in good condition while the other temporary serious condition.
The explosion damaged at least three other cars in the parking garage. Police say the explosion was so powerful it blew out windows in an elevator about 100 feet away.
The parking garage does not appear to have sustained any structural damage.

Since the cause of the incident is unknown, it is impossible to drawn case-specific lesson learnt. However, not only transporting a hydrogen tank loose in a car is illegal, to leave it in an underground parking is definitively a very bad practice.