Ukraine's day began violently when pro-Russian forces downed two helicopters in the city of Slovyansk, and things got worse hours later in the port city of Odessa. The exact number differs in various accounts, but somewhere between 30 and 40 people were killed when a fire broke out in a building there. Police haven't released details on how the fire started or even who the victims were, but the blaze followed rioting between pro-Ukraine and pro-Russia groups in the city, reports Reuters. The AP quotes Ukraine media reports as saying that the pro-Kiev group broke up an encampment of their rivals outside the building, and the pro-Russian group then took refuge inside it. The fire broke out soon after, with the best guess being that a Molotov cocktail set it off, either intentionally or by accident.
The heaviest fighting of the day, however, continued to take place in Slovyansk. Ukraine troops had control of the outskirts by evening, reports the New York Times, and were expected to continue their push tomorrow. The Wall Street Journal notes that US ambassador Samantha Power has expressed concern about "very alarming words from Russian diplomats" about the need for peacekeeping. Moscow used the same rationale for previous invasions of Georgia and Moldova, notes the Journal. Also today, President Obama and Germany's Angela Merkel warned that Russia faced new sanctions if it escalated tensions. (Read more Russia stories.)