Verizon technicians and network staff were investigating the situation but couldn’t yet confirm what caused the problem or the extent of the disruption, a company spokesman said Tuesday.

DownDetector, a real-time monitoring service, showed a surge in reports of service interruptions Tuesday from those providers, with a spillover to popular websites like Google, YouTube and Zoom. The problems appeared to be concentrated on the East Coast.

The pandemic has made broadband outages especially difficult. High-speed internet connections have become a lifeline during the Covid-19 pandemic as millions of office staff, students, health-care professionals and others use broadband to work remotely.

Verizon’s problems also are ill-timed for a company that just reported disappointing results on Tuesday morning.

Read more: Verizon falls after posting disappointing subscriber figures

The carrier’s shares slipped as much as 3.4% to $56.46, marking its biggest intraday decline since March 2020.

In response to questions about the blackout, Verizon reported on Twitter that it suffered a cut in a fiber line in the Brooklyn area, without offering an estimated time of repair. User comments suggest the outage was widespread.