The famed Lake Shore Drive in downtown Chicago closed suddenly Feb. 11 due to “structural emergencies,” as crews scrambled to temporarily fix a cracked steel beam that supports the roadway. A permanent solution is weeks away.

Outside Boston, chunks of concrete fell from a bridge structure on Feb. 7, prompting the closure of lanes on I-90 and resulting in major traffic delays. On the same day, concrete also fell from the Richmond-San Raphael Bridge in Northern California, causing gridlock. Luckily, no one was injured in either case.