SAN DIEGO -- It was supposed to be just a routine stop in dry dock for maintenance, but what happened aboard the USS Lake Champlain in November of last year was anything but routine.

"First, it's about getting that job done. Safety is a distant second," said former safety inspector William Washington.

Washington was well-trained in hazardous materials and environmental technology, as well as confined space entry.

He was hired in September 2007 to work for Tecnico, a company in the business of "ship repair and alteration," according to its Web site.

It was Washington's job -- before work began -- to inspect confined spaces aboard a ship, enclosed areas that could trap hazardous gases and pose a risk to workers.

"Nobody knows what was in that tank. Jet fuel flows all through that ship," said Washington.

Harmful gases were inside a tank aboard the Lake Champlain on Nov. 10, 2007. When welders began their work, the gases ignited. A flash fire caused serious burns to one worker and three others suffered minor burns.

10News' Steve Atkinson asked Washington, "Could this explosion have been prevented?"

Washington answered, "Yeah. All they had to do was check the space."

Washington said Tecnico was granted a big contract by Nassco, a major ship builder based in San Diego, to do repair work aboard the Lake Champlain.

Washington claims Tecnico employees were told everyday to shine and be early. If they got this one right, other contracts would follow.

Before the explosion, Washington said he inspected the tank.

"My recommendation was to call in the marine chemist first to let him certify the space," said Washington.

But Washington said his recommendations were ignored by a Nassco employee, saying it would slow down repairs and add unneeded expenses.

Two days later, Washington said he was fired by Tecnico in a move to stay in good standing with Nassco.

"He said, 'Sign here.' I said, 'What's this?' He said, 'You're being terminated for getting in a verbal dispute with our customer Nassco,'" said Washington.

Washington denied he ever raised his voice to the Nassco employee. He was fired on Friday, Nov. 9, and the explosion happened the very next day.

A federal investigation is now taking place and Washington is suing both Nassco and Tecnico.

10News asked Tecnico's San Diego office for a comment but was simply told, "No comment," and they hung up on them.

10News called Tecnico's corporate offices in Virginia, but calls were never returned.

Nassco said it could not comment about the incident because of litigation, but did tell 10News, "It (the incident) has helped our employees understand the issues of handling torches in confined spaces."