Toxic Fog Drifts Over Area

A railroad tank car rupture in Somerville sent a huge white cloud of toxic gas drifting over parts of that city, Cambridge and Boston yesterday, forcing thousands to flee their homes and jobs, and sending 100 victims to local hospitals. local hospitals.

Police evacuated nearly 10,000 residents from parts of Somerville yesterday, while in nearby East Cambridge officials bused students to schools in other parts of the city, away from the haze of phosphorous tricloride.

Workers covered the last puddles of leaked phosphorus trichloride with dirt last night, and officials said the area was out of immediate danger as evacuated residents began to return to their homes.

A Boston and Maine locomotive crashed into a tank car on a railroad siding in the Somerville train yard at 9 a.m. yesterday, cutting a large gash in the side of the 13,000 gallon tank and sending the liquid streaming out.

City workers using bulldozers dug a makeshift trench next to the car in an attempt to drain the liquid, which mixed with the moisture in the air to form an acrid, choking gas.

A Rescue Operation

Rescue workers and others in the path of the cloud reported breathing difficulty and skin irritation. Medical officials said prolonged contact with the gas might cause liver, kidney and lung damage.

Rescuers rushed 130 people to both Somerville and Massachusetts General Hospitals. At least a dozen were treated for inhalation of the gas at Somerville's Central Hospital, and several more went to the emergency room at Cambridge Hospital.

Only nine people were injured seriously enough to require overnight hospitalization.

By late evening yesterday, most of the liquid had been pumped into two tank trucks and taken away from the site.

Workers smothered the remaining chemical with dirt and sand last night.

Health officials decided to cover the remaining chemicals instead of hosing down the soil and dispersing the trichloride into the air. "We decided in favor of a smaller containment problem over a longer term," Somerville Mayor Eugene Brune told a press conference last night.

Early morning winds sent the gas floating down a narrow, predominantly industrial corridor and out towards Boston Harbor, but a mid-afternoon wind shift forced the evacuation of several thousand from the Cross St. section of Somerville.

Somerville officials reported rescue shelters had been set up at three elementary schools, Tufts University, and the city's National Guard armory.

Barricades were thrown up across the Tobin Bridge, the Monsignor O'Brien and McGrath highways and sections of Washington St. in Somerville, snarling traffic all day throughout the Boston area.

Police blocked off Cambridge St. past Inman Square in Cambridge for a short time yesterday morning but reopened the thoroughfare within half an hour.

Worried about the possibility that the moderate wind might carry the taxic fog toward the city, Cambridge officials prepared yesterday morning for the possible evacuation of East Cambridge. Though officials abandoned that plan late in the morning, city manager James L. Sullivan did order students moved from the Gore St., Webster, Morse, Kennedy and Harrington schools to other parts of the city.

Sullivan also directed housing officials to move residents of the Miller River and Truman high-rise elderly housing complexes to lower floors and to close all windows and shut off air circulation systems in the buildings.

During the morning hours, when the cloud was the thickest, the winds sent the gas up to an attitude of nearly 600 feet within a half mile of the accident.

Helicopters circled the scene measuring the gas release, and, on the advice of officials, air circulation systems were turned off in several Boston skyscrapers, police said.

The phosphorous trichloride, a colorless liquid used in water treatment by the Everett plant of the Monsanto Chemical Corporation, streamed steadily down the side of the ruptured car yesterday morning.

Collecting in pools at the base of the car, the liquid appeared to "boil" and mixed with moisture in the air to form the gaseous cloud.

Firemen may have exacerbated the problem by hosing the pools, causing more of the liquid to rise into the sky, sources on the scene said.

Three bulldozers worked to dig a drainage trench in the ground next to the damaged car.

Pump It Up

Firemen in gas masks shoveled debris off the track to help the liquid drain off into the pit, from which workers later pumped it into a waiting tank truck.

The flow from the damaged car slowed shortly after 1 p.m., after the level of liquid in the tank fell below the gash. Workers also attempted to plug the leak with insulation material.

Several rail yard workers were overcome with smoke when the liquid first began to pour from the car.

"The fumes almost knocked me down--I was choking and crying," Norman A. Lally, general agent of the train yard who was sitting in a trailer 15 feet from the tank car when the accident occurred, said yesterday.

Lally said it was not known which train car was moving when the accident occurred, but other witnesses said the engine sideswiped the tank car, gashing its side.

The Department of Transportation Railway Administration will conduct an investigation of the causes of the accident, Phil Gibbons, a spokesman for the agency, said yesterday.

Police, fire and rescue units from towns as distant as Lynn rushed to the scene to aid in the evacuation effort.

Patrol cars cruised up and down neighborhood streets asking residents to leave their homes. In East Cambridge, police blocked all entrances to Somerville