(TNS) — Superintendent Alberto Carvalho said a cyberattack, in addition to Monday’s software glitch, were responsible for Miami-Dade County Public Schools’ disastrous first two days of its virtual start to an already surreal school year.

Carvalho made the shocking announcement outside School Board headquarters in downtown Miami, Fla., late Tuesday afternoon. He said the district suffered a distributed denial of service (DDoS) attack Monday morning, simultaneously with a software glitch that blocked access to the district’s servers, rendering multiple online school district features useless and teaching nearly impossible.

Carvalho said the FBI and Secret Service have been called in and Comcast, the school district’s internet provider, was subpoenaed around 3 p.m. He said he did not know who the perpetrator may be, but vowed to prosecute to the fullest extent of the law.

“Yesterday I said I was frustrated and disappointed,” Carvalho said. “Today, I am frustrated and angry.” He said the software glitch, which he described as an operating system software with bad code that needed to be fixed, was “100% resolved and optimized,’‘ adding that the switch worked “fairly well” on Tuesday. The simultaneous DDoS attack, he said, created a bottleneck of system requests that overwhelmed servers and locked students and teachers out.

“We are absolutely convinced this is a contributing factor to yesterday’s problem,” Carvalho said. “This absolutely caused additional stress.”

He said whoever conducted the cyberattack did not hack in or penetrate district servers. It is not clear if the attack affected My School Online, the school district’s new and controversial learning platform developed by K12, a for-profiit education conglomerate.

Carvalho compared the high-profile attack to the cyberattack that struck when Florida’s public schools debuted online standardized testing in 2015. Cyberattacks against schools have increased because they are viewed as easy targets.

In 2019, there were 348 cyberattacks against U.S. schools, almost three times the level in 2018, according to an article in EdTech.

Early Tuesday, a school district spokeswoman said the district’s Internet service via Comcast was “intermittently interrupted” Tuesday morning but was soon resolved. She said 160,000 students and over 10,000 teachers were logged onto the K12 platform. Miami-Dade Schools has approximately 275,000 students and nearly 20,000 teachers.

“Given this took place during the beginning of school, we understand how important connectivity is for virtual learning during this unprecedented time,” said Comcast’s vice president of public relations, Mindy Kramer. “We are continuing to monitor the situation and are working with the school district and law enforcement to ensure this doesn’t happen again.”

Carvalho was reluctant to address issues with K12. Many teachers and students received error messages throughout the day that said the system was down for “emergency maintenance.”

Even through backdoor links the district provided, teachers, students and parents were greeted with error messages. Entire class periods were wasted. Some classes had a teacher with no students, others had students but no teacher. Many pivoted to Zoom video chats and reported having no issues there.

Teachers and students took to social media Tuesday to mock — or at least, make light of — the outages. Students made TikTok videos and teachers and parents circulated memes of “banana dog” — the scruffy pup adorning a banana print tee in the stock photo found on the ever-present K12 error page.

Carvalho said the kindergarten through fifth grade element of K-12 was down for 30 minutes. The sixth grade through 12th grade portion was down for about an hour. He said district officials were in conversation with representatives from K12 Tuesday.

Chief Academic Officer Marie Izquierdo said 107,000 students and teachers were logged on between 8:30 a.m. and 9:30 a.m. Tuesday, and 103,000 logged on between 9:30 and 10:30 a.m. Another 67,300 logged on at 10:30 a.m.

She said the school district marked 218,000 students as successfully getting through the system and connecting at some point. For those special classes that use Microsoft Teams, 71,700 students logged in. Many teachers turned to Zoom or Microsoft Teams in the wake of the disruptions.

Carvalho said the district has “detected challenges and optimization needs” with the My School Online platform, but that the school district received assurances from the company that it will work optimally.

“We’re going to hold the company accountable,” he said.

K12, the company that runs the My School Online platform, received a $15 million no-bid contract over the summer without board approval. That contract has not been made public.

Carvalho said the contract will be discussed at the virtual School Board committee meetings on Wednesday.

“There is no mystery in the contract,” he said.

Carvalho changed his tone on Cisco, the Silicon Valley tech giant responsible for the software glitch, calling it an “incredible partner.”

Looking forward to tomorrow, Carvalho said, “I am now confident we have identified two sets of problems and two sets of solutions” and the school experience Wednesday will “improve dramatically.”

That’s far different from Monday and Tuesday, when thousands of the district’s students and teachers could not sign onto their virtual classrooms for the first two days of school.

The school district did not open its classrooms to students due to the coronavirus pandemic. Carvalho said Monday that the district would look to reopen classrooms in mid-September, providing the number of new COVID-19 cases continue to trend downward in Miami-Dade County.

By 11 a.m. Tuesday, teachers and students were greeted with a new error message on K12: “Due to emergency maintenance, some or all courses may be unavailable. Teams were working to resolve as quickly as possible.”

One teacher at Miami Central Senior High said she wasted the entire first period of school trying to log on, even while using her Internet connection from home. Any breakthroughs to the site quickly came and went. She then spent her time calling students’ parents to get them on Zoom.

Another teacher at Coral Reef Senior High said she logged into the K12 website directly at 7:45 a.m., but wasn’t joined by a student until 8:40 a.m. Later, 24 out of her 26 students were learning in K12. They accessed the platform via the school district’s portal, a program called Clever and the Azure backdoor.

Some were able to pivot to hosting classes via Zoom, the video chat platform.

“Not even trying K12 for last block,” texted the Reef teacher, who dropped a Zoom link into the Newrow video chat on the K12 platform for students to click on. “Waiting to know K12 is perfect before I go back. Kids are DONE.”

©2020 Miami Herald. Distributed by Tribune Content Agency, LLC.