regretfully the crew abandoned ship and transferred themselves and as much equipment as they could salvage to another vessel.
regretfully, the effect of this legislation would be far less economical than its language.
Word Origin and History for regretfully
1640s, "full of regret," from regret + -ful. Regretfully, properly "with regret," incorrectly used in place of regrettably "it is to be regretted that; calling for regret" since at least 1965. "A regrettable use, prob. after HOPEFULLY adv.2" [OED].