Seven-year-old Yitzhak Gross, one of two siblings hospitalized in critical condition last week after an exterminator treated their family home in Jerusalem with a poisonous substance, opened his eyes on Saturday and, for the first time since his hospitalization, was responding to external stimuli.

Afterwards he was sedated again, and hospital staff said that he and his brother, five-year-old Michael, were still in serious condition, with no marked improvement.

Their parents, Shimon and Michal, who lost two girls to the toxin, remained at their side throughout the weekend, praying.

The girls, Avigail and Yael, aged 1 and 4, were laid to rest on Thursday at Jerusalem’s Har Hamenuhot cemetery.

The exterminator suspected of negligence in the girls’ death was released from custody on Friday. He was slated to remain in house arrest at the home of his attorney, Moshe Shiffman, until Monday.

Avigail and Yael Gross (photo credit: Courtesy family)

Avigail and Yael Gross (photo credit: Courtesy family)

During a visit to the family’s home in the Givat Mordechai neighborhood last Monday, he allegedly  used aluminum phosphide, which, when mixed with water, reacts to release phosphine, an extremely harmful gas.

The exterminator, whose identity has been suppressed by a gag order, had used the material before without any problem, Shiffman said on Thursday at the remand hearing.

The exterminator reportedly left a container of the poisonous material inside a room that he sealed with masking tape, intending to return to continue his work.

Shiffman said on Thursday that his client was an experienced professional who did not deserve to remain under arrest.

“Just after this happened and even before the police got to him, he rushed to the hospital to help pass on information about the material he used to the doctors,” the lawyer said. “This is a substance he’s used for a long time. It’s tablets and it’s not clear to me that there’s a limit on the amount you can use.”

Shimon and Michal Gross, who lost two daughters after an exterminator treated their house, speak to the media Thursday (screen capture: Channel 2)

Shimon and Michal Gross, who lost two daughters after an exterminator treated their house, speak to the media Thursday (screen capture: Channel 2)

After falling ill, the girls were rushed to the hospital on Wednesday along with the rest of their family, but doctors were unable to save their lives.

The boys suffered severe damage to their cardiac muscles, and doctors cautioned that there was no known antidote to the toxin.

On Saturday, the family asked that the public join their prayers for the boys, Yitzhak and Michael.