Which L2s halted blocks this week?

TLDR

Starknet (STRK) is the only major Layer 2 that halted block production this week.

1. Starknet paused blocks for over four hours before resuming, per a media report.
2. Coverage this week centers on Starknet; other L2s show no verified full halts in the past 7 days in major outlets, with prior incidents referenced in a roundup.
3. Flow halted and restarted after an exploit, but Flow is an L1, not an L2, per a news update.

Deep Dive

1. Starknet Halt

Starknet halted block production for more than four hours and then restored normal operations after a software fix and rollback. Reports detail a start of degradation near 09:53 UTC and full resumption around 14:02 UTC, with the team committing to a post?mortem and prevention steps in follow?ups. See the incident coverage and an additional market outlet report.

2. Others This Week

Major outlets this week did not report full block halts on Base, Arbitrum, ethereum/">Optimism, zkSync, Linea, Scroll, Polygon zkEVM, or Blast. Several reports reference earlier 20242025 incidents on those L2s, but not fresh halts in the last 7 days. See the context note in this roundup.

3. Flow Is Not L2

Flow halted and later resumed block production as part of a recovery plan after a $3.9 million exploit. This is relevant operationally, but Flow is a Layer 1 chain and not an Ethereum L2. Details are in a news update.

Conclusion

This weeks confirmed L2 block halt was on Starknet, which recovered operations after several hours. Other L2s did not show verified full halts in major coverage over the past 7 days. If you rely on specific networks, monitor their official status pages and post?mortems to manage operational risk during and after incidents.