My husband delivers oxygen tanks for a company. A oxygen tank blew up on him in front of our kids. He received 3rd degree burns. are they liable

It is impossible to tell from your inquiry whether your husband's employer is liable. Among other things, one would need to know whether your husband was acting in the course and furtherance of his employment of the time of the explosion (in which case the employer would not be liable, but your husband would be eligible for workers compensation), what, if anything, he was doing with the tank, and who owned the tank and who did what to it. Because liability issues like this are often complex, you shoudl consult with an attorney. You cannot obtain reliable information from a computer.