Rashi explains that, indeed, Hashem had a wealth of ways to save Noach. The Teivah, Ark, was not for Noach; rather, Noach worked for one hundred and twenty years building this incredibly large boat, so that the curious spectators would question Noach, who would impart the message of impending doom. Perhaps this would motivate them to repent. In other words, the sole purpose of the Ark was to inspire the people to do teshuvah, repent. Hashem’s boundless compassion for His creations is so great that He held off the punishment which they certainly deserved, just because they might repent.
We derive a powerful lesson from here. Check your messages. Things happen which, for the most part, are inexplicable. If we were to open our eyes and engage our brain, we might realize that Hashem is speaking to us. For example, something happens to a friend, a member of the community, even someone whom we do not know, but we know someone who does know him. This person has sustained a frightening experience, a serious medical incident, an economic loss. Does it ever enter our minds that perhaps Hashem is sending us a message? Are we guilty of infractions similar to those attributed to the other person? In other words, are we like him, and Hashem is demonstrating His compassion by sending us a subtle message to get our act together before we follow in the other fellow’s footsteps?