BOSTON (AP) – The ink company under investigation in a Danvers chemical explosion last month made some its employees available for interviews by federal investigators Tuesday after being threatened with subpoenas.

U.S. Chemical Safety Board officials planned to interview more employees from CAI Inc. Wednesday at the firm’s Georgetown plant.

The CSB had threatened to use its subpoena power against the company and its employees after CAI representatives failed to show up for walkthrough of the explosion site Saturday and after CSB was denied interview access to the employees on Monday.

“We welcome this cooperation from the company today. It represents progress for the CSB investigation and allows us to begin to get to the bottom of why this horrific explosion occurred,” CSB lead investigator John Vorderbrueggen said.

CAI spokeswoman Cheryl McLarney denied any stonewalling, saying the company has made employees available for interviews and provided data to the state fire marshal, state police, Danvers fire investigators, and the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives.

She said CAI is trying to do the same with the CSB, but has to arrange employee interviews based on needs of the company and the family schedules of workers.

“We had officers of CAI and employees on the scene within an hour of the explosion,” said CAI spokeswoman Cheryl McLarney. “We have been working with authorities since then. To say we have not been cooperating is not a fair characterization.”

State Fire Marshal Stephen Coan said CAI has been cooperative with his investigators.

CSB investigators have had a tough time conducting their work since they first arrived in Danvers after the Nov. 22 pre-dawn explosion. No one was killed or seriously hurt by the blast, tremors from which were felt as far away as New Hampshire.

Local and state investigators refused to allow their federal counterparts to enter the blast site for a full week. At the time, Danvers Fire Chief James Tutko expressed displeasure over the federal probers offering a hypothetical cause for the explosion before setting foot on the site. Tutko said the CSB was “uninvited” and “unwelcome.”

A truce in the jurisdictional dispute was reached last week after the state fire marshal’s office ruled out criminal conduct as a factor in the explosion.

Town Manager Wayne Marquis said 23 families had been able to move back into their houses as of Tuesday night in the Danversport neighborhood around the explosion site. Marquis said 45 families remain displaced because their homes require more extensive repairs.

AP-ES-12-05-06 1846EST