THE STATE WEBSITE for finding an appointment for a COVID-19 vaccine crashed Thursday morning as a torrent of people 65 and above rushed to sign up, the latest chapter in the Baker administration’s ongoing difficulty responding to the pandemic.

Many people who logged on to the website at 8 a.m. were met with a message saying “this application crashed” and to try again later. By about 8:25 a.m. it was possible to get into the website, but it appeared all the appointments had been booked at major mass vaccination sites and other locations. Later in the morning the website was accessible but no appointments were available except in Greenfield.

Frustration with the teetering website drew a fresh round of criticism of Gov. Charlie Baker from other state officials who have already shown an unusual willingness in recent days to take shots at the two-term Republican governor. It’s been a new experience for Baker, who has enjoyed stratospheric approval ratings for most of his tenure.

Early in the morning state officials blamed the website crash on “extremely high traffic and volume” and said new appointments had not been posted yet and would be released throughout the morning. Just before midday the mass.gov website said “all appointments for mass vaccination locations in Springfield, Danvers, Natick, and Dartmouth have been booked for the next week. More appointments for these sites will be made available next week. Additional appointments at other locations will posted throughout the day today. We apologize for the website challenges and are working to rectify these issues as soon as possible.”

Baker said during a noon radio interview on GBH that 20,000 appointments in those communities had been filled. Another 50,000 appointments were slated to go up once the website was fixed, but he did not say when that would be. As of mid-afternoon, only a handful of appointments were available, all in the western part of the state.

At 8:30 p.m., the state’s COVID-19 command center put out a statement apologizing for the technical difficulties. The statement said that despite the problems, 60,000 appointments were ultimately booked for the week at mass vaccination sites, leaving no remaining appointments at Fenway, Foxboro, Danvers, Natick, Dartmouth or Springfield. A small number of other appointments – at pharmacies and regional collaboratives – will continue to be posted in the coming days.

State officials said the vendor operating the site, Prep Mod, addressed the problems, and state officials are now pressure testing the site.

Prep Mod issued a statement at the same time accepting responsibility for the debacle. “We deeply regret what happened today in Massachusetts and are committed to ensuring this does not happen again,” the company said.

Prep Mod attributed the delays to “a sudden and unprecedented surge in traffic to the site,” which the system did not scale fast enough to accommodate. It said the site is now operating normally.

Baker had said on Wednesday that he thought the state was ready for the press of appointment requests that were expected as the administration began allowing roughly 1 million people age 65-74 and those with two or more underlying health conditions to make appointments. However, he had warned that the appointments could go fast, pointing out that the federal government had given the state only 139,000 first doses.

“My hair’s on fire about the whole thing,” Baker said on GBH on Thursday. “I can’t even begin to tell you how pissed off I am. People are working really hard to get it fixed. People did a lot of work preparing for this but clearly they didn’t do enough.”

He acknowledged that changes need to be made moving forward. “We’ve made a lot of progress in the last 2 or 3 weeks but this is not satisfactory. It’s not even — it’s awful and it’s going to get fixed. I’m going to work very hard to make sure it doesn’t happen again.”

Senate President Karen Spilka and House Speaker Ron Mariano, both Democrats, both said they were “disappointed” in the website problems. In statements, each mentioned a legislative oversight hearing that is scheduled for next week.

“I am deeply disappointed that today so many Massachusetts residents are feeling frustration and anger on a day when we should be experiencing hope. I hear it and I feel it too,” Spilka said. “The Senate and House are holding a public, livestreamed oversight hearing on Thursday, February 25 and we expect answers from those responsible for this failure. The Administration must deliver a better experience for our residents, who have already dealt with so much anxiety and disruption.”

Mariano said as one of the residents who became eligible to book his vaccine appointment on Thursday, “I was disappointed to experience difficulties with the VaxFinder website. We all have the responsibility to get our shots as soon as we can.” Mariano said the hearing will “address problems that delay the fair and accessible distribution of vaccines.”

Gus Bickford, the chair of the Massachusetts Democratic Party, seized on the website snafu to attack Baker as being incompetent.

“Just yesterday, not 24 hours ago, Charlie Baker expressed confidence in the state’s readiness to handle the increase in demand for the vaccine that was to come today. This morning, as newly eligible Massachusetts residents attempted to access the state run website to make a vaccine appointment, they encountered another broken system,” Bickford said. “Anything short of a direct apology for this latest disaster is another complete cop out from the governor who has mastered the art of dodging responsibility.”

Michelle Berrios-Hudson logged onto her computer a little before 8 a.m. in anticipation of the rush to schedule an appointment for her mother-in-law, a 75-year-old Lawrence resident who had become eligible for a shot earlier but struggled to sign up. “It was 7:51 to be exact and I found that the site had crashed,” Berrios-Hudson said in an interview. “I spent two hours trying every few seconds to access the site,” she said.

At times, she was able to see appointment details about vaccination sites at Fenway and Danvers, but by the time she got a verification code text from Curative, the company facilitating shots at the Danvers site, no appointments were available on the site, and it crashed again. The Danvers site at one point showed 660 available appointments, but they soon disappeared.

Tom Torrey, 70, who is newly eligible for the vaccine because of both his age and two co-morbidities — diabetes and heart disease — said the website crashed “several times” starting at 8 a.m. At one point, he got as far as selecting a date 10 times, each time answering several health questions and giving his cell number to get an appointment text confirmation, only to have the site crash again, erasing it all. “It’s very frustrating,” said Torrey, a Salisbury resident.

“Getting an appointment to be immunized during a pandemic shouldn’t be like scoring concert tickets online,” said Foxborough state Sen. Paul Feeney in a Thursday morning Facebook post, calling the situation, “a nightmare.”

Asked on GBH about the large amount of criticism he has gotten over the vaccine rollout, Baker said while his job ended up being “way more complicated than I thought it was going be,” any difficulties he is facing pale in comparison to what many Massachusetts residents are going through. “The agony and the pain and the suffering and the tumult and the crisis that COVID and some of decisions we had to make to deal with it has created for people makes any of the rockiness those of us in public life had to deal with feel like nothing by comparison,” Baker said.