More than 250 firefighters battled the huge blaze for nearly four hours late yesterday at the yard owned by the General American Transportation Co., 220 E 22nd St., San Pedro.

Flames roared hundreds of feet into the air and exploding tanks rocketed skyward like space missiles, fire officials said. "One tank took off like a Titan missile then fell to earth," a fireman said.

Smoke from the inferno covered the harbor area for miles and blocked out the setting sun.

Flames erupted at 5:57 p.m. and were contained at 9:02 p.m.

A company spokesman said be believes the fire was caused by a large tank truck which entered the yard to load up with vinyl acetate, then bumped into a loading dock and caught fire. Flames quickly spread to the nearest 30,000-gallon tank.

The 100-foot high, 20-foot diameter container exploded and rocketed 300 feet into the air.

Within minutes nearby tanks blew like fireworks, hurtling huge balls of orange and red flames and black smoke into the air.

"This is the worst chemical fire I've ever seen, said Deputy Los Angeles Fire Chief Richard Carriger. "There have been worse oil fires, however," he added.

Two firemen were injured, none seriously, as they fought the blaze with the irritant chemicals forming puddles at their feet. Both were treated at Bay Harbor Hospital. Fumes from burning chemicals also caused many firemen to use breathing apparatus.

When the fire was contained, firemen were herded to a special area to wash the chemicals from their feet and legs. Most soot-covered firefighters, and some newsmen, stripped to their underwear in order to be hosed down, and washed with a special anti-bacterial soap.

In the aftermath of the blaze, which emptied 20 of the 73 chemical tanks, federal, state and local officials now fear major pollution damage from the substances which spilled into the harbor.

Investigation of the problem is expected to extend through the week by U.S. Coast Guard, the State Fish and Game Department and other agencies.

Officials said there would be no surface slick since most of the chemicals are water soluble. However, they did not discount the possibility that marine life could be killed.

Endangered by the flames were a string of Southern Pacific Railroad tank cars which stood on tracks alongside burning tanks. The company dispatched a locomotive to the area and pulled the cars to safety. Firemen were successful in protecting a nearby warehouse.

One cargo vessel, the 10,000 ton State of Punjab, and two private cabin cruisers were ordered moved by the Coast Guard.

Thirty-three city fire department companies were aided by three Coast Guard fire boats, three helicopters and six companies of county firemen, including huge foam and deluge rigs, including one from the crash crew at Los Angeles International Airport.

Fire was confined to the storage yard which is directly across the channel from the popular Ports of Call shopping center and tourist attraction. Storage tanks, painted in various pastel colors, contained solvents and acetates for overseas shipment. Highly flammable chemicals are owned by several manufacturing companies.

Sgt. Albert Lugo, who said he was the first policeman on the scene,described the scene as "one of the most awesome things I've ever seen. Tank after tank blew up as the fire spread.

"Just as I arrived, one of the big tall chemical tanks went up in the air with a woosh...It went as high as three telephone poles and broke up when it came back."