LEWISTON, Maine — Longtime state Sen. Margaret Craven, D-Lewiston, said Thursday that she will not seek re-election after 12 years of legislative service. She is retiring to take care of her ailing husband.

“Representing the hardworking people of Lewiston has been a joy,” Craven wrote in a statement, “My service in both the House and the Senate has been challenging and rewarding, and even once I leave the Senate, I will continue to fight for working people and for those in our community who are most vulnerable and in the greatest need of our support. I would like to express my sincerest gratitude to my legislative colleagues, our hardworking staff and most importantly, the people of the city I am proud to call my home.”

Late in the day Thursday, word was just starting to get around. The reaction was shock and sadness mingled with admiration.

“I was just crushed when I heard,” said state Rep. Peggy Rotundo, D-Lewiston. “No one has served the people of Lewiston and the people of Maine with greater compassion or with a greater work ethic. Margaret is tireless. She has an enormous heart, and she has always kept the best interest of the people as her focus.”

Craven was first elected to the Senate in 2008 after serving three terms in the Maine House of Representatives. She represents District 16 in the Maine Senate, which consists solely of the city of Lewiston. She is Senate chairwoman of the Health and Human Services Committee and a member of the Government Oversight Committee.

“She has always been a voice for the voiceless, for the most vulnerable,” Rotundo said. “I’m a big fan of Margaret. I got to see that hard work and passion firsthand.”

During her tenure in the Legislature, Craven was an advocate for economic development, long-term care, services for people with developmental disabilities, early childhood intervention and substance-abuse prevention. She has worked for John F. Murphy Homes since 1988 in various capacities.

In 2012, Craven was awarded the Champion’s Award from the Alzheimer’s Association. She also sponsored legislation to build an adult day care facility in Lewiston for veterans and for their spouses who need a break from providing care.

Born and raised in Ireland, Craven has lived in Lewiston for more than 40 years. She and her husband, Jim, have two grown sons and three grandsons. The couple has been married nearly 50 years.

The matter of who will replace Craven was a big unknown Thursday.

“Someone has some very big shoes to fill,” Rotundo said.