An elderly woman who said she heard a siren yesterday and went to the door of her North Arlington home "to see whose house was on fire" found a crowd of onlookers staring at a gaping hole in the earth of her front yard.

To her dismay, she learned from officials and workmen that steel pilings shoring up Interstate Rte. 66, under construction about 20 feet from her North Taylor Street residence, had collapsed and that she would have to evacuate.

No one was injured in the cavein, which is under investigation by state and county officials. One Arlington official said heavy rains earlier this week may have contributed to the collapse.

Charles Scott, construction supervisor for Expressway Constructors, the Sterling firm building a portion of he highway, said the collapse was discovered by excavation crews.

Scott said some weaknesses in the shoring holding the pilings had been detected two months ago. That weakness was corrected by adding stone to help hold the pilings in place, Scott said.

One Arlington official who viewed the scene said that holes in the earth as deep as 25 feet could be seen from the yards of two homes located adjacent to the highway construction.

Scott said his firm will pay all temporary relocation expenses for the residents, who are staying in a nearby motel. They may be able to return to their homes by Friday evening, he said.

The elderly woman, who requested anonymity, said she is eager to return to the home where she has lived since 1940.

"It's very comfortable here in the motel and you can't get mad," she said. "I think this collapse is kind of like what happened at Mt. St. Helens. It's an act of God. I'm just glad no one was hurt."