http://revach.net/article.php?id=3396

Section: Parshas HaShavua   Category: Quick Vort
Parshas Bishalach: The Song Of Death
When The Bnei Yisroel was crossing the Yam Suf the Malachei HaShares wanted to say Shira.  Hashem said to them (Megila 10b), "Ma'asei Yadai Tavu BaYAm V'Atem Omrim Shira?", my creations are drowning in the sea and you want to sing Shira?  This is understood to mean that since their is destruction of Hashem's creations, even though it is well deserved, nevertheless it is not the time to rejoice.

Another pshat attributed to Rav Heshel of Cracow is as follows.  When Hashem wiped out Sancherev's massive army poised for an attack on Yerushalayim there was no noise and no destruction.  They simply did not wake up in the morning.  The gemara Sanhedrin (95b) says that Hashem let their human ears here the Shira of the Malachei HaShares and this incredible kedusha killed them.

Similarly here, the Malachim requested that Hashem open up the ears of the Mitzrim so they would die from hearing their shira.  Hashem answered them that "Ma'asei Yadai Tavu BaYAm" they drowned my children in the Nilus.  The rules of Mida K'Neged Mida demand that they are punished with drowning, and you want to kill them instantly with shira alone?